No... CloudFlare and nginx don't really have anything specifically to do with OpenSSL.
The issue is that OpenSSL 1.1.0 has massively changed their API and many hooks that used to work with 1.0.2 are completely gone.
In the case of Deluge compiles, these hooks are determined by boost libs. Boost fixed this issue in version 1.62. However, Ubuntu 16.04 does not package a version of Boost higher than 1.58. Therefore to continue using user-compiled versions of Deluge, a user has two options: Compile boost 1.62 or greater yourself or downgrade OpenSSL to version 1.0.2 (the version still shipped by default in Ubuntu 16.04) via package pinning