great product, disastrous name

You're at the sharp end, so you probably have more of a perspective but I don't think there is anything wrong with the name per se more the material used to explain the offerings isn't that effective. I mean Secure Productive Enterprise wasn't exactly inspiring as names go, at least Microsoft 365 ties in with a few things, like Office 365.

Unfortunately, the best materials I have seen that's much better explaining Microsoft 365 is for partners only and not for the public.  There are so many combinations, like all the add-ons available to Microsoft 365 Business, having to work it out is almost impossible otherwise.  I don't think they need to change the name just have better guidance on what it is, how it compares to the rest, what it isn't etc, oh having a trial easily available wouldn't hurt either.  The official https://docs.microsoft.com/en-us/microsoft-365/ is ok but there still seems something missing.