At minimum already it appears Vince has learned two things;
1. Don't try and get the league running within a year. Leads to less time for teams to actually get their **** together, have camp, players learn the system, etc. Given the rumors have this starting in 2020 (assuming in the same window the old league had calendar wise), that gives them a full 2 years to get the ship ready for sailing, or so to speak
2. If you have a platform for your league, it won't die painfully. What ultimately killed the XFL on the first go round was the fact once NBC dumped it, it had nowhere to go. Theoretically, if that were to happen again this time, Vince would have a pretty good amount of alternative options to get his product out there, unlike in 2001.
I mean, the Arena League is somehow still kicking despite dying like what, twice in the last decade already? It gets by alright on mostly being broadcasted on streaming stuff/ESPN 45