Need I say more, this is utterly astounding. So 8.5 was released before ‘the next maintenance release’ and still no fix.
I was actually informed by steinberg support that the next maintenance release for Cubase Pro 8.03 would hopefully include the fix. Have not included the email contents here as the emails ask you not to do this.
Your experience reinforces the general opprobrium surrounding 8.5.
With some caution and hesitation with a very brief test with the new 8.0.35 maintenance release (22-12-2015):
So far with large templates the expression maps do seem to be recalling correctly when the track has previously been disabled (as well as adding new tracks with Expression Maps and enabling disabling)
Watch this space, need to do some more testing to see if this is reliable.
If it is truly fixed then 8.0.35 at the moment is ahead of 8.5…
UPDATE 23/12/2015: still not fixed in 8.0.35
Still not fixed in 8.5.1 maintenance release.
Could very easily get a ban here, but I refrain from using expletives.
Sorry state of affairs.