This is framed so negatively toward LastPass, which is unfortunate. They stopped all usage of correct passwords they believed were compromised, which is exactly what I'd want them to do in this situation. Them warning users their master passwords are compromised is a good thing! Yet it's framed as though they're admitting to something.
"However, users receiving these warnings have stated that their passwords are unique to LastPass and not used elsewhere." That's really hard to verify. I think most users would say that rather than admit they re-used passwords (or used similar passwords that were easy to reverse engineer). Since there only seems to be 2-3 reports of this, and they're self-reported and not cited, it doesn't seem like LastPass was compromised.
I'm not saying I like LastPass (I use 1Password and find LastPass to be much worse), but I haven't seen any indication at this point that LastPass has been compromised at all.
(To be clear, it's very possible I'm wrong and this message won't age well. But so far, it seems like LastPass is doing its job, and I'd want to see more than this before jumping on the blame-LastPass bandwagon.)