I see this going one of two ways.
Perhaps we have yet to see DeBoer's true system, he hasn't been at any FBS stop too long, despite the transfer portal and 26 5th and 6th year players at Washington, he might just never have put his true staff and team together. I tend to think not because of the portal and him seeming to be able to get almost everyone he wanted on staff at Alabama. But, it is still possible he just hasn't been able to place the keystone yet, the thing that makes it all work together on offense.
In that case, I'm curious to see who else he brings in and what changes he makes to facilitate that.
The other, is kind of as you alluded to and I would add wouldn't be unlike what Saban must have had in mind when he tried to hire Grubb. He wasn't going to just run DeBoer/Grubb's scheme. He was as he did with all the other OC's going to adapt it to Alabama and the SEC. That's what I'm kind of what I'm hoping for, that fusion of SEC style physicality and his west coast offense.
On another thing though that makes this difficult, is being in the playoff makes dealing with staff and roster issues really hard. If Alabama lost, they'd already be eyeing the portal and the staff changes, but as it is they are very much in a "don't rock the boat" type situation Saban got stuck in as well.
Saban had to make choices that sometimes were not the best long-term, because he was focused on competing for championships. So it's easy to say oh DeBoer should do this with his staff, or what have you, but what I think we all want the most is for Alabama to compete for a championship, and they have a shot this year to do that so the rest might just have to wait.