next Battlefield should have:

I don't remember BF3 having a lean mechanic but it's been years since I last played. 

I am not so sure I agree with weather effects unless you are talking about more grounded things like sandstorms, rain, and wind.... Kinda like BF4 did with Gulf of Oman and Paracel Storm. If you're talking about bringing back the ridiculous tornado then please NO!

I'm also not big on the tablet call in mechanic unless this would be squad leader calling in a supply drop or cruise missile strike, similar to BFV. But straight up vehicle drops I prefer flag and base spawns. 

Of all the things you listed, the ones I think that would be the greatest to the game are:

BFV Movement mechanics, Squad perks, and fortification/build mechanics.

I think Levolution could be okay on certain maps, but it can't be forced. If certain maps would not benefit from it then it shouldn't happen on those maps. I'm hopeful that with the perceived increased level of destruction and micro-destruction that it won't be necessary. Bad Company 2 was notorious for being able to level a whole map which while fun, wasn't good for map design. BF3 scaled this back which was the right call and then BF4 brought in the levolution mechanic on top of this. It was a bit gimmicky in most cases but it was still fun in places such as Siege of Shanghai. Maybe the next iteration of destruction will take a page out of the Finals game design where pathways can be opened up via destruction. This would mostly benefit tight urban maps the most, but could make those maps very interesting to play every round. Some of the leaked footage and short reveals from EA themselves suggest that this may be the case