During my one month travel I used my chip-based VISA- and MasterCard all in all 10 times. The only time I was turned down was at the hotel Jagua in Cienfuegos.
I travelled to Cuba at the time when the new chip-based VISA- and MasterCard were introduced.
In Denmark and in other places around the world the new long expiration date caused many problems, but I had no problem with my non-USA cards in Cuba - that is except the episode described under “Short change”.
However, you should know that if you want to draw money on your card at a bank in Varadero, you’ll probably end up waiting in line with the other tourists for ½-1 hour - and that’s outside in the sun!