The reporting requirements for RRSPs were changed greatly for the better about ten years ago, but I'm not sure where you got the idea that the FBAR no longer applied. (Note: technically the new online Treasury form is a "FinCen Form 114", but it is still referred to as an FBAR, even on the form itself.) The 8938 replaced the former 8891 but was not well advertised. I got caught on that one myself not long after and had to send in a couple of years' amendments (which, for me, did not change any numbers, it was just a missing form). If you use TT it prompts you for foreign account information and will generate the 8938 if it's required. The FBAR, of course, is done separately because it's not an IRS form; it is now only online.
There are ways to get yourself back on track, such as FBAR amnesty forms. For a thorough review of the background, as well as information on moving forward, I suggest you start with this article by a tax lawyer who specializes in cross-border issues (https://hodgen.com/rrsps-and-the-irs/ , updated in 2023), and possibly also consult a tax/accounting expert familiar with this area for verification. I would have suggested you contact the IRS, but a) it's a terrible time of year to do that; and b) it will be nearly impossible to get hold of anyone who has the first clue about handling RRSP reporting. Those amended filings I mentioned above ended up in different IRS offices. One handled it correctly - i.e. simply acknowledge receipt of the additional form - but the other was so confused I had to use the letter from the first one and explain the situation to get the second one unstuck. (Once upon a time I had a really excellent phone conversation with the IRS attorney who worked on improving the RRSP rules, but sadly, I see he died several years ago.)
This is not a fatal situation, but you really should not ignore it.
