The bug
You can equip saddles on horses by right-clicking on them, I don't think that this was possible in 1.15.2. Not sure whether this is intended or not but this seems to be more of an oversight.
This doesn't affect other rideable mobs (that is not a pig/strider) like donkeys, llamas, trader llamas, skeleton horses or even the unused zombie horses. This causes issues like horse armor becoming invisible (MC-182919).
To reproduce
Spawn and tame a horse
Right-click with a saddle
→ ❌ The saddle is equipped on the horse
Videos
(In 1.15.2)
[media]
(In the latest snapshot)
[media]Related issues
relates to
Attachments
Comments

Pretty sure it's intended, if not, I say keep it.