I suspect this is going to make a smaller splash in Commander than it will in Modern itself
This does narrow the number of combos that you can use, but there are some ways to go off with Primal Prayers
Being both gold and basically always needing a dork in play to do much of much leaves this with not all that many decks that can play it
The Support Tutors/Card Quality/Dig Vampiric Tutor 10 Combo decks love a tutor
They can be solved fairly easily, and, unless combined with the other half of their combos (proliferation of counters, Mycosynth Lattice, Wheel of Fortune), dont have a huge impact on the game for more than a couple of turns
Fans of Limited, either rejoice, or crumple in fear, because whatever you open, you can play, from Armageddon to Force of Will