Ah, Le Grove. That tweet is the same signature move he's had forever, the one where you process whatever anxiety you have about the present situation by pretending it's all part of some unlikely master plan. He did it for the entirety of the Wenger years too.
Selling Xhaka to Leverkusen while bringing in £200m+ of established prime age players isn't "aging down the squad".
There is an obvious master plan: do what we did last season, and do it with a bigger, better educated and better rounded squad, with tried and tested tactical options in place when bad form, injury, fixture congestion and fatigue strike.
If I were Arteta I would be sitting round figuring out "What does the XI look like if x and y are out injured or suspended?" for every possible x and y in the first team squad.
Last season we had an epic 50 point half season, then an also-ran 34 point half season. If we can play this season in two 45 point halves, we can win the league.