In the 'user-right' notifications, I suggest one or both of:
1. Add a secondary link to the log-entry
This will allow users to read the full message if it is truncated, and to access any links that appear within it.
The link would be something like: http://en.wikipedia.beta.wmflabs.org/w/index.php?title=Special%3ALog&type=rights&user=Etonkovidova&page=User%3AET59 (If I am User:ET59)
Labelled as something like: Learn more, or Log (translations), or User rights log (translations - much longer)
2. Remove truncation
The "reason" is limited to 256 bytes, plus is unlikely to ever be excessively verbose, but might include links. (I tested. It's 256 bytes, not characters)
This would also help if any links are contained after the truncation-point (which users may not realize they should look for). E.g. I might write (with ^ as truncation point)
Here are some new user-rights! You can find more details about this in th^e page [[long page title]]
Note A: We currently include clickable links in the excerpt. I think that's good. But if they are planned (?) to be removed, solution #1 would be even more necessary.
Note B: See examples of userrights logs at https://en.wikipedia.org/w/index.php?title=Special%3ALog&type=rights and https://de.wikipedia.org/w/index.php?title=Special%3ALog&type=rights - most are very short, or even empty, but sometimes they are long, and they often include links.