I would rather state it as there can be really saved persons in any Christian church so called, but would be very much insisting that they come to the real understanding of the Gospel as per calvinism...

God saved me while I was in no church background, and I went from AOG/Free Church/ To now Baptist, and moved from a westley viewpoint to now reformed on salvation proper, so could there not being many like me still in the middle of their transformation into holding calvinistic teachings now?