This is true for my son's smaller club as well. Early invites went out already, and most of the existing players received them, with the requirement to accept or reject by end of January (ish). I don't think they sent out any early rejections, but I know some of the weaker players did not get invites to register early, and were instead asked to attend the tryouts (which are next week).
Based on what the club did last year, I'd guess that most (if not all) of those players would still get invites to play with the club next year also, unless they get a large influx of better players or something (and perhaps even if they do). My impression is that the club was more trying to just "lock in" the stronger players early, before they had a chance to look around (in essence, forcing them to commit before the tryout period was open in order to guarantee a spot on the team, or risk getting dropped during try outs). The generous reading is that they are doing early team capacity planning for coaching decisions; the pragmatic view is that they are applying pressure on parents of kids who might have other/better options elsewhere, before they are allowed to explore them.
I know at least a couple kids who received early invites who are not accepting them, because they want to explore other options after the tryout window opens, even though they will probably still try to stay with the club. Others are taking the offers to not risk getting dropped later. But I estimate that at least 50% of the team slots will be filled by tryouts, if not more.