Honey bottle can be consumed in Creative mode

This might be intended; you can consume water bottles in creative as well.

but the water bottle doesn't turn into an empty bottle, as like the honey bottle

Good point. Added that to the ticket.

Honey bottles now cure poison when consumed. Another reason why this might be intended.

The issue was fixed in 19w35a, you can no longer drink the bottles on creative. It probably was fixed while fixing MC-159574

Cannot confirm, I'm still able to drink honey in Creative mode in 19w35a.

As of 19w35a you can still drink honey in Creative mode, though the item won't be consumed. So, same as for other potions/water bottles.