Fox were airing towards that as a possibility with their CTD system, however IMO, having ridden for the last 7or8 seasons on tracloc equipped bikes, the seatpost has to remain seperate.
I currently run a Genius 700 with a DOSS post, whilst it makes sense (sometimes) to have 3 distinct characteristics:
1) Full post height – full low speed compression damping on fork and locked out rear
2) 40mm drop on post – some low speed compression damping fork – traction rear
3) full post drop – fork wide open – full travel rear
there are too many scenarios outside of those 3 examples where I want independent control of the post height.. i.e. pedalling over mildly tech terrain, I want fork and shock compliance, but full post height.
CTD fork and TC/full travel control on the same lever (Twin loc)