Yeah, I agree with Brian that it was stupid to wait, but with this timing, I'm guessing Biden is just farting in the elevator before getting off.
I'm certainly no lawyer, but a reading of this makes it pretty clear that Congress has been empowered to impose a time limit on ratification since SCOTUS's decision in 1921. This did not apply to the 27th Amendment since that Congress put no time limit on its ratification.
https://constitution.congress.gov/browse/essay/artV-4-2-1/ALDE_00013054/
Now, I do think there's a valid question about why such a restriction would be put on ratification in the first place. I suppose you could make the argument that if an amendment can't get ratified by X number of states within a certain period of time, then it's not worth passage. Of course, that's a dubious proposition when a chunk of the country is too entrenched in its own prejudices.
Regardless, I applaud shining a light on the issue, so let's see if the Dems can make any hay from it (narrator: they can't).
I'd appreciate it if anyone could point to the ABA language providing an opinion on why the amendment actually should be valid.