Although some people may be just waking up to this issue now, there are actually already Rabbanim who specialize in yuchsin when there are complicated issues.
It should rather be standard practice in every community, if it isnt alread, (and by many communities it certainly is) to check seder yuchsin by every marriage.
There are actual halachos about accepting someones word if a stranger comes to town and they say they are jewish and want aliyos/ say they are a Kohen etc.