Danos doesn’t have enough projects remaining:
Unless there’s a tier 4 upgrade quest that I’m missing but even then it doesn’t make sense for the Sacrament Reborn challenge to be in the game since the number of builder projects will always be finite so at some point the players will run out.
Danos T4 worker upgrade is also redundant for now especially given how many resources it requires and the lackluster benefit it gives (esp late endgame with most of the builder projects already completed), unless you make it so the T4 workers can be brought over into other realms to complete those projects faster but even then it is redundant and most players will not use it.