I created and played two games in parallel with the same seed (Cf Environment), one Creative and one Survival.
When I got to the End and had killed sufficient dragons to open all the end gateways, I found 10 End cities within easy reach of the gateway destinations. However, in Survival mode, only 9 of the cities generated, and of those two had large chunks missing. So, in Survival mode, 30% of the cities were either non-existent or severely damaged.
To reproduce:
The damage could be replicated by deleting the associated region file(s) to force the game to re-generate the region.
Workaround:
Copy the affected region file(s) from the unaffected Creative game. Note this caused some of the end gateways to dump you in the void, but this can be worked round too.
Related issues
duplicates
Comments
migrated
Although this has now been marked as a duplicate of MC-96998, I don't think it is. I read that issue before I filed this report, and the description of the bug there seems to me to be quite different to what I experienced. In particular, what I saw only happens in Survival mode, and does not seem to me to be directly connected with chunk loading, because it is reproducible by deleting the appropriate region files and forcing the server to re-create the region.