We have been still using enterprise 18 so downloaded 19, as I assume this is the missing component on getting past this really annoying email. We've logged in to intuit ID and to merchant ID and saw no action needing to be taken in either.
It has to be said the email and related support article are equally vague. Intuit could have simply put a link and said click here to verify your account or whatever else needs to be done. It's totally not obvious what needs to happen and how to resolve it.
Calling the support number yielded a 30-35 minute time so no. Called and emailed our "priority support" agent who we've never spoken to because she is the new one and at least the prior one was in touch so maybe that also needs to be fixed.