SD to HD conversion at a cost

I purchased a few films years ago that were only available in SD. The HD version has been released, but Apple say you have to buy the title again.

Conversely, when 4K became available, Apple automatically gave consumers the 4K title when they had purchased HD.

Apple are being inconsistent with their application of consumer support. If you bought a film in SD when HD wasn't available, it should have been updated in format, just like how we all got 4K upgrades as that version hadn't been available before.