Reading a letter during sacrament meeting is good, but I don't think it's sufficient. They should still add protections to the software to keep inappropriate names from being submitted. Maybe they are in the process of doing that.
I found this part of the letter to be interesting.
"Without exception, Church members must not submit for proxy temple ordinances any names from unauthorized groups, such as celebrities and Jewish Holocaust victims,"
Does this mean that descendants of holocaust victims will no longer be able to submit their ancestors? It does say "Without exception."