Nah, rubbish.
The way to lock-out Arsenal, and any other team, is to increase your fixed revenue streams - because they're the only guaranteed source of income. No business worth its salt budgets based on, what is in effect 'bonus money'. To my knowledge, Arsenal don't budget to be in the CL, so - with that in mind - whether they were in the CL or not is largely irrelevant.
We have to grow our business by investing in bricks and mortar, and that means the stadium with its fixed revenue streams. That's the long-term strategic position. Even if I took your point about 'reducing the gap; wages and revenues' - that gap is only closed, until such time as we have to commit ourselves to significant financial pressure with the stadium build.
The rule of thumb is: stop worrying about what Arsenal are doing - fudge um. Our priorities are a lot more closer to home.