We have been given ample reason not to trust anything Bungie says at this point. This recent interview is just them telling us what we want to hear because there are a lot of contradictions going on. Like how up until today they were incapable of remake the vaulted content but now it's no problem at all.
It was never a question of capability, it was simply a matter of the suits refusing to do anything that didn't result in obvious tangible financial gain. Giving players back content that they'd previously paid for, or content that had already been made free? That's just spending money for no benefit. Better to just pump out another dozen Eververse sets and rake in the dosh. They were completely ignorant to the value of player trust.
(If you're referring to the lawsuit stuff, just because they didn't have a ready build on hand doesn't mean they didn't still have the files. They probably figured videos of the campaign would suffice rather than go to the trouble of spinning up an old version of the game just to demonstrate it for the court, only for them to get egg on their face when the court wouldn't let them. We don't know the terms of the settlement, but considering that the Sunrise project shows how little effort it would have been, they could've spent less if they'd just paid a couple of engineers to crank that out in a week.)
With that said, the problem was always the difference in the engine between pre- and post-Beyond Light. It's not like you can copy and paste the old content and have everything just work. Like the article says, lighting, scripting, and other things need to be reworked to make all those old activities functional in the modern engine, on top of (I would hope) revamping the old rewards with things like origin traits, tiered loot, and (in the case of year 1 loot) random perk rolls, to say nothing of updating interfaces, re-adding triumphs, and other miscellaneous work. Sunrise works for the old content because of how the scripting functions; post-Beyond Light, the scripting was changed to have more functions handled server-side, so they don't have an easy way to learn how to build those activities.
It would be foolish to blindly trust Bungie with anything at this point, but the fact they've even confirmed that they're going to bring this stuff back is a step in the right direction. We'll just have to see what happens in the months ahead.
Oh man, seeing the Director with every single destination node is gonna be wild.