In the 28 years the Champions League has been in existence Barca have qualified for it 27 times. The only time they didn't qualify was in the 1995/96 season. There is very little difference between Barca looking to secure future funding based on their participation in the competition as there is with Premier League clubs securing funding against future TV revenue from participating in the Premier League even though they do not know if they qualify to play in the Premier League in those future years. PL clubs do this very regularly.
It's a little different. The PL teams doing this just need to finish 1-17th.
Barcelona must finish Top 4 for multiple seasons to achieve it. Just because they have before doesn't mean they will continue to especially with how much mess they might end up in.