Keeping scenario instances relevant. Celestial difficulty?

With most scenario’s designed for early expansion content. how will it Hold up with Celestial dungeon that will be expanded on with each season.
Heroic difficulty will add some challenge but not for long, and only 6 of the 15 instances will have the difficulty.

I remember speedrunning them for easy 60 justice points, and a random 450/463 ilvl equipment we would Disenchant or vendor. there is just not much to make it intresting for people to do them after they outgeared Heroic dungeons. and will become a dead feature very quickly.

can we expect improvement on them in the future? give ALL scenario’s heroic/mythic difficulty or make it Relevant with the Celestial dungeons and Reward currency for the current season’s vendor with similair affix.

only people who will be in the Que for scenario are lvl 85-89 Leveling alts. and Fresh 90’s
that will sometimes get a heroic raid geared main rushing the instance and complain how his team suck with Green questing or normal dungeon gear.