Company moving 401k match to yearly lump sum

Long story short, as of 2025, my company is no longer making 401k matches per pay period, but is instead aggregating what would be matched each pay period into a lump sum that is contributed to the 401k match portion at the beginning of the following year. I know that at the end, the total is essentially the same but I see two problems:

  1. The money that was matched each pay period would no longer be able to compound over the year.
  2. This may discourage workers from finding better opportunities if the company is no longer obligated to provide the match if the employee leaves mid-year. (Note: I don't know this to be the case, but no where in my company memo did they say that they would immediately match YTD amounts at the point of departure.)

Question: Is this even legal? I suppose so since companies aren't really required to even match... but I find it rather shady.