i think it looks like they'll be investing money in the short term but that we'll swiftly be returned to self-sufficiency. my theory as to whay they'd be willing to inject transfer funds is along the lines of:
1. regain CL revenues as quickly as possible. if £50m invested now gets us back in there next season then a huge portion will be repaid very quickly. god knows how much longer it'd take with no cash injection.
2. raise the profile and on-field performance, and therefore help off-field revenues, with an eye on FFP.
3. ultimately, they got a great but rather down at heel club for £300m. it seems logical to me that it's better to have a really competitive, thrving club for £350-400m investment, than a struggling and hamstrung one for £300m.
in short, we're in apparent need of investment, and doing nothing could be seen as a false economy.