I think this is one of those “just asking [misleading] questions” things.
Dude is a law professor, so it’s pretty easy for him to “see how.” There are predicate events and curing events written into the rule he cites. It seems like he is banking on people erroneously relying on his bonafides as a Harvard professor and not reading the NY rule (which is the only one that really matters).
To be disqualified under the rule:
1. the person has to qualify as a prospective client. (This appears to be the case).
2. It has to be the same or a substantially related matter. (In the standard lexicon, that would appear to be the case but I’m not sure how the NY Bar applies that language.)
3. The attorney has to have received harmful information during the consultation and even then there are a host of curing actions that the lawyer or firm can take that are set out in the next subpart.
If you think about it, it makes sense that a rule governing duties to prospective clients would be less broad than a rule governing former clients to prevent litigants from just consulting with a bunch of quality lawyers to dumb down the pool of potentials left for their opponents. And for a lot of other reasons.
You would still want the rule to provide enough security for prospective clients to be forthcoming about the issues.
There could still be an issue but Twitter dude is **** stirring, in my opinion.