I believe I can answer the OP since I use Carrara pretty much exclusively.

If DAZ stops supporting Poser (I think it's a stretch to think there's much concern about Poser and it's users in the DAZ organization anyway, but that's a different topic), then Poser users will do what I have always done - work around the minor annoyances created by using objects intended for another software package.

I would say that 95% of my content is Poser or DAZ centric.  This means things don't always import properly, shaders are nearly always off and morphs frequently don't work.  I won't give up the advantages of Carrara, so I just bring the content in any way I can, fix it, and save it in Carrara for future use.

This means clearing up bumps, highlights and properly assigning textures in shaders.
It involves opening items with external morphs in Poser, turning off external morphs, and saving them again so the bloody morphs work.
On the plus side, in Carrara it is very easy to make adjustments and new morphs for the mesh on the fly and then save them in the modified object file.

I suspect that is what Poser users will do if DAZ continues to move away from Poser interoperability.

On a final thought, this will create opportunities for "fixes" like the simple armpit correction.

Klebnor

Lotus 123 ~ S-Render ~ OS/2 WARP ~ IBM 8088 / 4.77 Mhz ~ Hercules Ultima graphics, Hitachi 10 MB HDD, 64K RAM, 12 in diagonal CRT Monitor (16 colors / 60 Hz refresh rate), 240 Watt PS, Dual 1.44 MB Floppies, 2 button mouse input device.  Beige horizontal case.  I don't display my unit.