David Kilpatrick on Photoclubalpha argumented with founded tech background dismisses the groundless myth that a shorter mount to focal plane register (body thickness) cause any problems with lens design.
In fact the E-mount makes it possible to design slightly smaller medium to long zooms and very much smaller wide-angles, and normal sized standard lenses. Where there is potential for Sony native lenses to be small, there’s very limited potential for this with DSLRs.
Thanks David for this!
P.S.: Also Photochirp explained some facts around the E-mount system.