I bought some RFM95 on AliExpress. They are cheaper than RFM95W but appear identical. Except for a blue marker dot on the bottom side near the “W”. Maybe there was a difference in the past but not anymore, except for that dot of blue marker (which anyone can either put there, or remove with some alcohol). 
Even the datasheet does not mention any differences. It only mentions RFM95(W), everywhere in the datasheet.