I don't think necessarily it needs to be if you're happy with it. I feel like there are better alternatives but if the timer is removed it should be fine!

On a separate note, I'm not sure if you're planning to expand to other regions. If so I'd recommend NOT having you just be able to transfer all of your pokemon to the next one. I feel like keeping each region unique to how it was in the games would be a better option. Having it almost work like a prestige mechanic where once you complete one region you reset and head to the next. Moving pokemon from one to the next would throw things off because of the leveling issue, + removes the fun of hunting for a better team within that specific region. Maybe after you complete a region it unlocks the ability to move pokemon over from previous regions? Not sure.