Hi, guys. I tried to answer first thing this morning, but somehow the forums would not accept my comment. The "post" (submit) button literally did nothing (on multiple browsers and different devices).
Here's what I had written:
Short answer: yes
Longer answer: Each update's uninstall can only revert to the previous one done. So the oldest one you keep (and those before it) will be the oldest you'll be able to revert to (after reverting to the more recently applied ones).
For some folks, they may well be ok to only be able to "go back" one.
I'd argue it's safe, though, for most folks to delete update backups that are more than a month old, as they'd not likely want to revert after such a long time. But each org should decide for itself. And this is why Adobe doesn't delete them for you.
And I can help assess and resolve these things directly and quickly, via remote consulting, for anyone interested.