Initial note: some feral cats do meow but please read on…
It is believed that cats have learned to meow as a form of communication with their human caretaker in making a demand for food normally.
As feral cats don’t have human caretakers they have not learned to meow and in any case in unmanaged colonies there’ll be nobody to meow to.
That said people also ask: “Why do feral cats meow?”. On the same theme, this must be because feral cats who meow have contact with humans, probably feral cat colony caretakers who are carrying out TNR programs. These cats will sometimes became friendly with their human caregivers who feed them. The feral cats become less feral and sometimes semi-domesticated. They learn to meow to their human caregivers.
Not much more to say. The answer turns on the idea that the cat’s meow is directed at people. Although, there are occasions when feral cats do meow to each other. One such occasion is when a friendly feral cat approaches another with their tail up to signal friendliness. The other does not respond and the tail up cat might then meow to attract its attention. This would be one of the few occasions when feral cats meow.
So, the idea that feral cats never meow is inaccurate. It is just that it appears that the meow is a learned vocalisation from domestic cat to person. Perhaps this vocalisation has entered the feral cat population via domestic cats who came to that population when they were abandoned.
I tend to agree with you that cats avoid calling attention to themselves in a way that could attract a predator from the distance or alert a prey creature of their presence. They learn quickly that certain things cause undesireable results. Hissing and a tap to the head is their form of negative commenting. When we thought all the TNR was completed 2 years ago, one was missed. She is very “wild” in behavior compared to the others. When she was trapped and four of her 5 kittens as well, one was missed until it was so old it had to be TNR instead of taken away for adoption like the others.
That one little wild girl came up to the feeding area and started making sounds as she approached food and every cat in the colony except her mother would place a paw or slap with a paw to the top of the head and deliver a HISSSSS. I believe they were training her to keep quiet. She no longer makes those sounds and does eat with the others now.
BTW – THAT ONE THAT IS A NATURAL was born in the wild and I have observed her since the mother started first weaning her by taking her in to the field and teaching how to catch bugs then later at around 8 weeks they all began following their mothers to the human provided food and that little girl would present herself about 6′ outside the feeding circle and walk back and forth a few times letting out a little meow then join the group. I always made myself a casual observer by not talking and just leaning on a wall so they would become easier to trap when the time came for the TNR people to come out and take care of that process.