I can't see how that would make sense at all. Arsenal have messed up this season but to say it's all part of a plan is complete madness. They have lots of players with big personalities who might look for a move if they don't get CL footy next season. Especially if it looks like they won't get it the season after as well.
Well no, I'm not saying they set out to miss the CL this year on purpose; there's no doubt they've underachieved this season, I just think they may have accepted to take the hit for this season, and the next possibly, knowing that long term will be more stable and solid for them to build on.
It's not completely unrealistic, clubs -like businesses- set out a plan, and it may just be Arsenal's outlook to cruise for a season or 2, and come back with a solid foundation, one not built on billionaire owners nor debts, to attack the league with gate receipts, sponsorship, and merchandise etc.
They may have lots of players with big personalities sure, but not necessarily worth as much (apart from Fabregas, and maybe Adebayor ?), they have let people go, and were still able to take the hit, so I don't know why the fear of an exodus should stop them if they wanted to plan for the future.