That’s simply incorrect in my experience.

In addition, most people have a multi-region player.

But, to the case at hand:

MMT is noted as “region free” on Amazon, as per the OP https://www.amazon.com/Magical-Mystery-Tour-Blu-ray-Region/dp/B00ED0S89S

YS is almost certainly the same. https://www.amazon.com/Yellow-Submarine-Blu-ray-Beatles/dp/B0079J28NW

So, your answer is not the OP’s issue.