I now have four, Poppa & Psycho, and Little Bill & Elephant (my daughter named them)
Poppa will let me know as soon as someone comes downstairs that he's in the need of some salad and Mom time, Psycho will only raise a fuss if he thinks he's missing out on something, and during "floor time" because he feels the need to follow me around, and will wheek to let me know that I'm moving faster than his little porker limbs can carry him.
Elephant & Little Bill though, are a whole other story. Elephant will wheek every time he hears the fridge open, a bag rattle, jingley bells, the cats meow, the rats make noise....Little Bill doesn't make much sound unless your scritching his butt, he likes that!

I know every pigger is different, I was just curious.

Also-Elephant will sound the panic alarm when I take the water bottle out to fill it, so I've had to buy a second so that they have one at all times, I have to rotate filling them, I cannot do it at the same time or he freaks out! I got these two from a neighbor who "lost the new" and mentioned to me that they "don't really mess with them much anymore, they're not as fun as we thought". So could it be that they've gone without water, and it's just panic that they think I may not bring it back?

I would say yes that could be it. That they have gone with water that when the bottle is taken its like OH NO NOW ITS GONE FOREVER, But looking at their situation they were in and how they were cared for anythign could alram them. I know if I didnt get much food or water and then see the bottle or bowl removed I wold freack out.
My females make noise all the time their diva and want ther time, the males not as much unless I get close to the cage and check on the others or look in to see their food water an hay situation they they start thinking there getting more then what they have not finished. Or they hear somthing like the back fridge open and or some that sounds like treats. Sometimes it can be just the new place, If they have not been given to much attechen from their prevouse owners they could be freacked out if you move the bowl 2 inches as all is new to them with the love they are getting now compared to not. My old pig ma-gee would carry on a conversation with me were as the rest dont really except the girls till they get what they want and the boys or they scratches and loved on.
do they seem to do it as much now since you have been doing the water bottle rotation? If not then I would say it was fear of them not thinking they were getting more but how long has it been you had them? if it hasnt been that long then they are proably still getting use to it and it could take some time. If not depends how long they have gone threw what they have it could be a learned behavoir being so long, like animals that have been abused or mistreated for so long it can take some time.
Little bill and elphent thats from Bill cosby that cartoon of him as a little kid lol that is so cute.

my guinea pigs hardly ever wheek, only if i've been on holiday (which is when my neighbor looks after them) they wheek when i get back and go see them.

Our piggies (Janus and Livingston) are really loud! They've learned certain noises mean food, so if they hear a plastic bag rustle or the fridge open, they start wheeking. Since we're in a small, one bedroom apartment right now, they also squeak sometimes when one of us turns in our sleep, I supposed because they think they're going to get food. They're very spoiled. :p

LOL My Pigs are very spoiled too, we did get one more Pig, his name is Ponyo Sosuke (again, my daughter named him) He was the son of the daughter of Poppa, err so his Grandfather/Father. When I rescued them, the two females were pregnant, and went to live with a friend, the other Mom pig lost her three babies, but considering that Ponyo's sister is a grab bag of genetic mutation, I guess that's a good thing.

Elephant still sounds the alarm when you take out his water bottle, but I do put a smaller hamster sized one in while I'm getting their larger bottle cleaned and filled, so that seems to calm him a bit.

Our guinea pigs scream at us . They wheek SO loud...and pretty much whenever someone walks by the cage! Which is a lot since it's in a high traffic part of the house (they seem to really enjoy the social interaction, interestingly).

I Have 11 Piggies, 1 Rabbit And 2 Chinchillas, How Do I Share Pics Of Them Here?

Everytime I even touch their bag of hay/pellets, they start wheeking like crazing and doing laps around the cage They even do it when I walk near the cage, haha! At night time, when it's time for their veggies, they know. They wheek to remind me

My pigs will squeak everytime they hear me open the door or walk by their cage! They get even louder if they hear me rattle a bag or make a clicking sound (which means it's veggie time). So my pigs are chattering quite often.

When I'm hoovering, and he's hungry, his squeaks very, very loudly.