Can Pokemon above level 40 be used in non-Master Leagues?

Niantic have stated that Pokemon above level 40 (excluding the Best Buddy boost) cannot be used in Master League for the time being. Does this restriction also apply to the other Battle Leagues, such as Great/Ultra League?

Am asking first before I decide to power-up my Medicham beyond level 40 for Great League use.

Solution 1:

Yes, these Pokemon can be used in non-Master leagues. At the time of this answer, they can also be used in Master league.

For Great League, powering up Medicham beyond level 40 is optimal since for even a perfect IV Medicham, it can still gain some levels without exceeding the 1500 CP cap.