We've got documented cases in the wild of youtube adding 5 second timer, as well as experimenting with 3 video limits for adblock users, not to mention the cat and mouse game of breaking scraper-oriented tools like Newpipe. So it's happened before, and on-the-ground evidence of historical precedent and a straight look at incentives tell us more than assumed psychological states.
But you do seem to be strengthening my comment -- when YouTube was implementing a 3 video limit for users blocking ads, they were doing so with a big huge message: "It looks like you may be using an ad blocker. Video playback will be blocked unless YouTube is allowlisted or the ad blocker is disabled."
That makes sense as a strategy, telling the user what to change. Silently using up more CPU doesn't.
Most of my examples cut against your interpretation rather than in favor of. The 5 second delay was discovered rather than announced, and same with Newpipe breaking, and I don't even agree that the video message had anything to do with a broad principle of always tying communications to user experience. If anything the history is the opposite, rotating through various forms of obstruction all of which nudge user behavior in various ways, perfectly agnostic to any principle of how it gets communicated.
It's pretty common sense to say that YouTube CPU usage will not be linked to adblocking for most people. Any more than a sunny day is linked to what you ate for dinner last night.
It's not psychology. It's just straightforward common sense.
You seem to be trying to obfuscate something here that is really quite simple.
Is it incompetence or sabotage? Who knows. The first rule of sabotage is to be indistinguishable from incompetence.
If someone sees, oh YouTube is making my computer hot, the last thing that's going to occur to them is, "wait let me try turning off my adblocker."
When corporations try to change people's incentives, they are obvious about it, so people know what to change.
In contrast, changing CPU usage on video playback for people who use adblockers and then not telling anyone is... just not a strategy that makes any sense at all.