I watched that youtube video of the guys discussing the issue and it was pretty enlightening. Not recasting T'Challa in the aftermath of the loss of Chadwick is still probably the best idea but not recasting him at all is a terrible idea.
Because he's just as important as Bruce Wayne, Peter Parker, Clark Kent or Tony Stark. And with none of these guys would their loss mean that they're permanently gone and their sister, cousin, etc..takes over indefinitely.
But that's what they're doing and it makes zero sense.
Because they could easily get another version of T'Challa from the multiverse, get a time variant, or create a modified clone (Clearly Wakanda can accomplish that).
As for Coogler wanting to hand the role to Shuri even before Chadwick's passing it shows that he doesn't get the character, doesn't like him, and didn't fully respect the character either.
Because you honestly need someone like Snyder, who fought for his movie, Charlie Cox, who fought for Daredevil to be properly done, and Ryan Reynolds who fought for an R-rate Deadpool and got it. From Disney. Who want to make every Marvel film unrealistically child friendly and comedic.
As for T'Challa he's literally supposed to be the wealthiest guy on earth (via Vibranium), one of the smartest guys on earth (He has multiple degrees and he's up there with Reed Richards and Bruce Banner in intelligence), and one of the best fighters on earth similar to batman.
But that's not what was show in Black Panther with him losing a one on one fight to a regular dude which made no sense. Him being outsmarted by regular villains makes no sense, and him not being as smart as Shuri was unrealistic as well.
And funnily enough the Black Panther cartoon that aired on BET was a far better version of Black Panther. Which Coogler couldn't or wouldn't do.
Some of the things in the show that T'Challa deals with and handles are:
An invasion of Wakanda by the US
An African nation invades as well
Ulysses Klaw invades with his minions
Juggernaut(!) invades with them
The Black Knight invades
And Radioactive Man along with them
He then basically deals with all the threats at the same time in a sequential manner showing brilliant strategic thinking while Shuri and others support him saving Wakanda.
Now it's doubtful Coogler ever watched the show. And if he did he ignored it.