I don't see the problem with a random gypsy woman informing Romania's savior about an inflicted curse. Gypsies aren't just nomads or thieves, they are also a spiritual people. More-so back in medieval times and they were all over the Romanian lands. Being gifted with 'sight' the woman could easily see Simon's suffering very clearly even before he knew what was going on. Not everything in the CV universe has to be interconnected with other people from other games/origin stories etc. If it were Sera from LoI why talk to Simon only and nobody else of the Belmont clan? If it were Rosaly, why talk to Simon when she had absolutely no connections with him but had every connection with Hector? And if it were Julia why talk to Simon when she could envision the future and see that everything turned out alright for him in the end thus not needing to inform him from beyond the grave?
There's no NEED for it, but it would be much more interesting than a blatant plot device. Also...
If it were
any random gypsy chick why talk to Simon only and nobody else of the Belmont clan? If it were
any random gypsy chick, why talk to Simon when she had absolutely no connections with him but had every connection with
her significant other? And if it were
any dead random gypsy chick why talk to Simon when she could envision the future and see that everything turned out alright for him in the end thus not needing to inform him from beyond the grave?