Nothing wrong with new sculpts and art. There are indeed a lot of kinda meh looking 'Mechs and sculpts, but in those case a lot can be corrected with new, better quality art and resculpting the 'Mechs, without redesigning the entire things.
As long as they're not MWO models or even too much much MWO-like. While animation gives them some life, as in HBS BattleTech, they still don't feel right to me, being too stiff, too much like walking tanks, not BattleTech at all.
BattleTech's roots are in Robotech and other such anime, as such humanoid robots are very much part of BT's identity, and that humanoid-part does include certain degree of freedom of movement walking tank depictions don't have.
BT does have place for more walking tank designs too, for example the Thanatos (along with variety of others). But it so from the beginning, turning existing designs to similar aesthetic is wrong.
The new art the classics got is great, and it would be nice to see more and more 'Mechs reworked for that, though not all need that treatment, naturally. The original Clan OmniMechs for example, they have extremely strong visual identity and pretty good art in TRO3050U (though i always prefer the original ortho art for some reason) (no comment on their minis, i don't own any).