They had no other choice but to disable survival as it is SO GOOD no one was doing many of the other activities

I think its a pretty god sign for the longevity of this game type and possible further developments like leaderboards for scores and so on.
Lots of people have come back Jedi - reddit is jam packed full of "just came back" threads but for OCUK specifically, you are right - not many of the old faces are coming back.
I tested 1.5 yesterday for about 6 hours before I had to shoot off, but I wanted to do it solo just like 1.4.
Quick and dirty summary is: Wt5 is a welcome and much needed addition as solo and group players will definitely have more of a challenge now, not by much but its a progressive increase.
The difference in max armour possible is negligible (61% max in wt4 vs 56.6% in wt5) so there will still be an element of run and gun as groups but the main difference is solo.
Scaling once again is slightly off. Tested a CM lexi, CM ug, hardest daily hvt and dz6 + extraction and whilst most of these were quite similar in terms of difficulty, the hvt was scaled way too high again. These were tested on wt4 gear with no modification and then tested again with wt5 gear.
The main point though is that the new world tier is still perfectly achievable for solo dudes, groups and people who don't have much time to sink into the game which is the main intention.
Much fun, cant wait to get back on on Tuesday.