I think they should. There would still be plenty of new contestants for the other two slots.

There was once a time when Wheel Of Fortune had returning champions in the 80's and 90's but in the 90's episodes they had the Friday Finals where the week's champions would compete for one final time. But it stopped in the 2000's
Bestie

Before 1996, Wheel of Fortune had a 3-day limit for returning champions, then from 1996 to 1998, a Friday Finals format was used where the top 3 winners from earlier in the week came back on the Friday show to win more.

Yes, Wheel of Fortune need to bring the returning championship format back.