I just tried… indeed topology had no problem updating by reimport assets… but… it did not ad the new morph targets…
I tested importing this mesh to a new folder just to check if morphs where exported and they did… so pressing “reimpot asset” just changes topology of mesh…but it doesn´t import the new morph targets from Maya… awefull
Bassicaly i have to re import the whole thing and do everything again just to add new morph targets… i think this is a good oportunity for Dev team to help users by also allowing to import also new morph targets on Unreal 4.19 by pressing reimport asset or adding a way to do it manually.