Based on how often silencers/suppressors are suggested it's clear people are looking for some options when it comes to the stealthiness of their weapons, but I don't think suppressors would make for interesting gameplay choices. However, if "Sound" were a stat assigned to and visible for each weapon and which dictated its spook radius I think that would give people some of what they're looking for in terms of stealth while also increasing the number of interesting choices to be made when picking a loadout.
As far as I know weapon sound/spook radius is currently based on the four weapon types, with the exception of the air rifle which is quieter and has a smaller spook radius than the other rifles. And that makes for an interesting choice: the air rifle has some significant limitations but the fact that it hardly alerts other animals nearby is very useful. Obviously none of the firearms would be as quiet as the air rifle, but a range of volumes would provide even more interesting decisions. A large caliber with otherwise good stats might be deemed overkill for a certain situation due to its loud report, for example.
I also think the recent changes to spook radius would have gone over better with the community if they hadn't affected all rifles equally (and you know, if the changes had been properly communicated). If people still had some options that were quieter I think it would have seemed more understandable. Though now that I'm thinking about it, I wouldn't be surprised if it turns out that the unannounced spook radius change was a sign that something like this is in the works, since we've seen before that version control in this game is not watertight. I'd be thrilled if that were the case.