Steam will probably accept it, but shipping updates will be a pain from what I have read so far the last time I checked because updates usually don’t go through the full Steam review process which would be required to ensure that no prohibited content is sneaked in via an update. I checked months ago. It is possible that this could have changed since the last time I checked.
If nothing changed since I last checked, you will need to fully debug the game before you release a Steam version.