In this particular case, I will very reluctantly have to come to Google's defense.
While its absolutely true that Google has been implementing a significant update to the YT/YTTV Roku platform codebase (from 1.x to 2.x for all supported models), which involves significant functionality enhancements and improvements (and larger app and (cobalt) library code) and has really been pushing it for the last 6 months, the updates to which have already exposed the poor memory management in RokuOS - in this case, it was Roku themselves that "pushed it over the limit" with the very large "Roku Browser" middleware app released a few days ago.
(One can only imagine/speculate what awaits us in terms of functionality with this very large "Roku Browser" module when next they thrust it upon us...)
FYI, checking for updates actually involves removing it, thus decreasing the memory load, and allowing an increased ability for (especially larger: YT/YTTV/ATV/AP) apps to run (assuming other decreased memory load, such as themes/screensavers).
(Aside: Google actually released very minor build revisions for all the impacted non-4K models yesterday in an attempt to help address the issue - after the "Roku Browser" initiated it)
To repeat: this can and will likely happen again with YT/YYTV/ATV/AP/etc updates in conjunction with middleware additions/updates, unless and until Roku's OS programmers fix the memory management issues, which will require firmware updates.