No dice for me, either. I have four 60k Ritz Carlton certificates expiring -- two on 6/24, and two on 8/24. They're refusing to budge. I've escalated it but still haven't heard back - when I call to inquire, they're saying it's "up to the loyalty department". I noted Marriott's policy about extending all certificates to January 2021 (combined with the fact that we feel unsafe traveling right now) and the representatives just guilt trip you about having had "plenty of time to use them before COVID started". Unfortunately, nothing is guaranteed with Marriott. If they don't extend them, I guess we'll just be book random properties near home and check in to get the elite nights for Platinum.
Update on my previous post. Once certs are extended, they won't extend them again - the blanket 1/31/21 extension was very deliberate -- only applying extensions to certificates that have never been extended before.
What didn't help is that Marriott waited over 2 weeks before replying to me via email (well after my certificates had expired). I got what looked like an automated reply about how certificates cannot be extended, and that upon review of my account, all certificates have an expiration date of 1/31/21. Clearly, nobody is putting in the effort to review the expired certificates, and I'm guessing this is just a copy+paste response to inquiries RE certificate extensions. I replied asking someone to re-read my original note, and received a second copy+paste response similar to the first.
In short, Marriott customer service won't give you the courtesy of reading your inquiries, so don't expect any help. I'm definitely not going to do any more paid stays with Marriott.