This release is not overly relevant to cube, or paper ones at least. If there is a card I really want to play with in a cube I am sure I can find or make a suitable proxy with which to do so with. I think largely I am glad that there is a release I can mostly ignore in terms of thought, effort, and obtaining. If arena can take away some of the intensity of card releases that is bonus. I get all the intrigue and excitement of a new release with interesting new cards complete with the ease of a reprint set.
As for the concept I am also all in favour. One of the advantages of an online game is a greater range of design space and it would be a waste not to explore it. That was one of the few things I liked about Hearthstone and basically the only thing it ever had over Magic. I am liking some of the initial mechanics I am seeing. I play very little Magic on Arena (I last did a couple of Kaldheim drafts when it came out) and this release is almost certainly going to get me back involved, if only for a bit.
As an aside one of the other advantages of an online version of the game is that you can fix things with card rebalancing. While that is very awkward when running online and paper formats in concert like standard any format involving Jumpstart: Historic Horizons can implement fixed cards without issue.
I am excited to see the rest of the set and how they make use of this new design space. I love how classic and iconic cards like Stormfront Pegasus and Lightning Bolt can be made relevant without direct power level concerns. I am also fine with some of the more random elements given the foolish dice stuff we have just been handed. This set seems like a win on all fronts and one of the few things I am wholly positive about that Wizards have done over the last few years. It might however be too much to hope that this is a turning point and the company is getting back to making good long term choices..