Honestly, I feel like the new Deft Explorer feature is still even a nerf from the original Natural Explorer feature it's trying to harken back to. For Natural Explorer you had double proficiency for ALL Intelligence and Wisdom skills you were proficient in (which for the Wisdom skills in particular you were probably going to have a couple of them at least) pertaining to your terrain of choice, on top of extra features you would gain after spending an hour in said terrain such as not being hindered by difficult terrain, not getting lost by mundane means, and other situational effects.
I feel like if they want to add terrain features, they need to be more integrated into the whole of the class, not just slapped on to replace a feature that basically did a similar thing but without needed to spend a day to attune for if you didn't already have the right one.
Heck, make a feature and call it Channel Terrain and given them features like resistances or the ability to summon a land spirit or something, I don't know. I don't have a problem with the terrain connection but make it more impactful or something,