Correct.
From the 11.5 NeRF:
• When -nocandodomain is not in effect, the statement CAN-DO("abc","abc@") evaluates to TRUE because both strings are interpreted as user abc in the blank domain.
• When -nocandodomain is in effect, the statement CAN-DO("abc","abc@") evaluates to FALSE.
I'm debating the pros and cons
I'd say the main "con" for moving to 11.5 now is the cost of your time for testing and implementation.
I see lots of "pros".
Support
With 11.5, you're moving to a release that has a guaranteed support lifetime of three years minimum. 10.2B is still supported, but technically that could change any day. That doesn't mean I
expect it to change very soon, but it's a roll of the dice whether it will still be supported a few years from now. Also, 11.5 can receive future service packs for bug fixes, performance improvements, and feature additions. According to the current plan, 10.2B will never receive another service pack.
Performance/access to new features
We're now well past the point where 10.2B had database feature parity with 11.x, apart from multi-tenant. For a while (11.1-11.2 time frame), some DB enhancements (e..g. idxbuild improvements, lruskips/lru2skips, prefetch query tuning params) were being back-ported to 10.2B, I think mainly because the combination of 10.2B's stability and 11.0's long development cycle resulted in a large 10.2B install base. Now the latest improvements are in 11.x only.
Obviously if you're writing your own code and care about new language/tooling/runtime features, they're only in v11 too. And entirely new products like Table Partitioning, Advanced Enterprise Database, and Pacific AppServer are only available in the later 11.x releases.
Future upgrades
If you move to v11 now, there's a good chance your next OE upgrade will be to a later release of 11.x, which is a relatively easy transition. No DB upgrade and very likely no recompile will be required. If you stay on 10.2B, your next upgrade is guaranteed to require recompile and DB changes.
Compatibility
At present, there is still enough of an install base for 10.2B that PSC is doing some OS certifications on 10.2B08 in addition to the recent 11.x releases. I would expect that trend of certifying 10.2B on new OSes to end within the next 12 months, or maybe even after the current certifications in the pipeline (Win10, Server 2016, etc.) are done. I don't have any inside information on that; it's just my guess based on conversations and announcements at PUG Challenge this year.
So if you choose to stay on 10.2B, near-term server replacement/provisioning could force you choose between moving to 11.x sooner than you expected or running 10.2B on an uncertified OS and hoping for the best.
