I think you might be talking about Brian Acton's loans to them? If so, yeah, they have to pay those off at some point, which begs the question why they took a loan in the first place. They were getting grants and things like that, so taking millions that they have to pay back, especially from a guy who sold WhatsApp to Facebook is... an interesting course of action.
I have no insights in how they use that money, but I sure hope they have not spent it already on 300 SF developer years, but rather treat it as an endowment. In the long run - spending 1-5 million every year, investing the rest - it shouldn't be too difficult to preserve the nominal value over such a long time frame.
> By the end of 2018, the loan had increased to $105,000,400, which is due to be repaid on February 28, 2068. The loan is unsecured and at 0% interest.
This is from Signal Foundation's Wikipedia. There is a schedule.
