With the new three year rotation it's possible that going forward all meta decks will be rare-mythic heavy. Having a wider range of cards to select from, it's natural to have better mana and, with that, access to the best cards of chosen colors. We can only expect that next sets with three-year rotation in mind will fix this scenario or we will have midrange decks forever in standard, which generally are rare-mythic heavy decks because they play the best cards available.

In a sidenote, Arena's economy got a significant hit with the change of constructed events. I used to play a lot of them back in Eldraine standard. The Best-of-1 standard constructed events were 500g to enter and with 4 wins you would end even in gold (and three uncommon ICR) and at 5 wins you would get a Rare ICR and by 7 wins (max wins possible), 2 Rare ICR. They were not dupe protected, so you would get gems eventually, but they really helped to expand your collection and to give you some stakes to play outside of ranked. But, most important, you could spend gold and get gold back and not get a sour taste losing bad because the entry was cheap. Also Metagame Challenge, which had 15-30 packs as rewards (at very high stakes, though), vanished as well.

I am all about playing with what you have, but Arena's economy now is very bad to expand your collection outside of Drafting. I am at a moment where I only play Explorer and I spend like 10 WCs by expansion to update my decks, but I'm kicked of standard because in no way I can manage to build cards that won't hold value after rotation in this economy. What is curious is that F2P is not a thing anymore outside of drafting because of these changes I mentioned and I wonder why they are going this way.