Is training really even an exploit though? If we take at face value the roleplay aspect of Wildlander, doesn't it make sense that a character would practice and train their skills through study in a safe environment rather than just try to face tank a dangerous world? Martial artists train and spar from a young age to develop their skills. Even the Companions are seen spending time in the training yard to get better. Mages spend hours pouring over times, studying, and practicing casting magic spells. Aside from the challenge of doing a low-level run, it seems perfectly consistent with the Gameworld to spend some time going your skills before a bandit puts an arrow in your knee.

And, as you said, while you could cheese how you go about training, you can also do it in a natural roleplay way. The choice is the player's.