I’ve heard of it going both ways, with either choice.
The nightmare scenario with sharing the name is that people will hate it and try to talk you out of it. This is very unlikely to happen if you wait until after the birth to announce the name. When the baby is not here yet, people will see a name choice as an option, as opposed to a solid decision - a “speak now or forever hold your peace” moment.
If you don’t share it now, the downside is only that if everyone loves it (and that’s a big IF), you’ll have fun calling the baby that publicly before the birth. That’s about it.
For me, knowing that my taste in names is non-traditional, I wouldn’t want to risk telling people and having them try to talk me out of it, or worse, make me feel badly about my choice. Personally, I have chosen to keep not only the name, but the gender a secret - which will be made even easier if we decide to let the gender be a surprise to us as well.
On the flip side, the two women I’ve known who’ve shared baby’s name before the birth lately have stuck with it. I don’t know if anyone’s given them grief about it, but obviously it wasn’t enough to change their mind.
There are many, many, many threads on this topic, but here’s one currently being discussed: