And how does that stop them? If they feel like pulling some shit, they will, I doubt the longterm viability is in mind, only the short term gains. "Kill 'em all and let God sort 'em out." Remember that they once demanded that a shareware copy of the game playable in-browser be taken down before.
If zenimax would fuck with the pwads, sourceports, and sources in general they would be destroying themselves both on legal and moral grounds.
In short, they can not screw with them because ID released them with licenses and permission to mod many years before zenimax ever touched anything ID. They can not revoke this without taking down every site, link, database, and server on the planet with the data on them, and they would have to dig trough anything made legal by ID to try and revoke it.
I wouldn't put it past them, sharks have no rhyme or reason besides money. TES modding is generally on newer games and they have a financial incentive NOT to attack modders, since it boosts game sales. While the classic id games still sell, they're old and don't sell nearly as much as they used to, so making modders pay insane legal fees and "compensation" is a bigger financial incentive.
TES modding is proof enough that they will leave PWADs alone, plus they have no reason to crack down on us. I think you are a bit paranoid.
Although, yes, I am a paranoid fuck in general.
It's important to note that the new Wolfenstein release date is entirely unrelated to when the Doom beta program will start, always read the fine print. I frankly consider the beta incentive a scam, while they don't lie about the Doom beta start date being unrelated, they only mention it in the fine print and never mention it in the advertising.
If Id fucks up Doom 4 I'd like Bethesda to give the rights to Machinegames. They seem to know what they are doing. We'll have conclusive proof of that in 6 days (can't wait)
Besides, if what those employee reviews are true about Doom 4's development, with constant reboots every few months, it's probably gonna be a while, and will probably suck anyway.