About the mlp sign on plushies. If its "the rule" it has to have mlp on the pony or the tag then I think a lot of g3 and g4 plushes are fake while they might not be.
As for the origin she was claimed to be Brasilian when I first heard about her and Teddy found hers in Florida. Otherwise she must have been more common over here with people getting ponies on holidays in those chinese knock-off stores. Or it was in one of those Eastern Europe countries discussed in a topic.
The first stage would be to try and find catalogue papertrails. Either a hasbro one, but more likely a toy one from somewhere around that time. I'm going to check the UK argos ones as I know one or two have plushes in, I'm not sure if I have those files on the PC or if I'm going to have to dig - but I don't think I can make a match to here.
I'm always sceptical of something until there's a paper trail. I still don't believe in CP Sundance and it took me about 12 years to believe in reverse Gusty. But I don't think we have enough information on this either way to confirm or deny at the moment, just speculate. The fact multiple have been found in various parts of the world is a good thing in it's favour.
Only recently we had the whole discussion about the sundance/pearl hybrid of which there are now four? known examples? For a long while that was also dismissed as a fakie but there are more than one and they've been found in low key situations that indicate they're probably princess hybrid ponies from the end of the line.
We just need more data with this. We need a paper trail of some kind.
Plush Honeycomb was only proven genuine in the eyes of the community when she was found with her paper tags still attached.