I feel changes like this are incrementally making the Web "theirs" and not "ours".
Separately, someone replied on here to me, a few months ago, that archive.org's policy for respecting -- or not -- robots.txt was in the process of changing.
I don't think that putting up a robots.txt policy should be able to retroactively remove from archive what was previously public. All the more so when the domain in question has changed hands.
But I expect this nonsense to continue. So, I only trust local copies.
Unfortunately, for me, killing the Scrapbook extension made them less convenient to collect.
I looked for alternatives, around the time Firefox stable transitioned. I recall that ScrapbookX was going to try to transition. There was language about writing to browser local storage, but that appeared to me to be too constrained for my use, as well as not yet being in place.
Since then, I've taken more cursory looks but not found a suitable extension. I recently learned about Wallabag, but it did not appear to have the same amount of facility; nonetheless, I want to set it up and give it a go.
I've been a little distracted, this winter. So, I've not problem solved like I should.
Streaming, clouds and DRM protection are fine for discovery, but if you love something, archive it. Storage is so cheap after all!