Give the possible Eureka 5.X its own weapon, and separate Relic from it

[Reynhart]

Now if the new content in 5.0 builds on the same elemental level as Eureka, then even Hydatos could be solo’ed (not BA though lol).

I think it should, but with a twist. Something like a "Key Item" you gain at the very beginning of ShadowBringers that allows you gain elemental Xp everywhere up to level 60. That way, by doing the SH MSQ, dungeons, etc, you could catch up and wouldn't have to do Eureka to enter the next content.

It should be noted, however, than PotD is required to enter HoH, so Eureka story being required might be a thing /shrug

The problem with the Eureka vs farming old content for the relic thing is that by removing the necessity of doing old content for the relic you've pretty much killed most of the incentive to do it for most people.

Roulettes already put you in old content, and Wondrous Tails is always updated with cap level HQ gear