Wab Kinew himself sums it up perfectly in a minute and a half, here:

https://youtube.com/watch?v=elfFAd-VC9U

The Indian Act reinforces a number of prejudices and injustices (including the name itself). Today Indigenous have a long court precedent to lean on to protect their treaty rights. Some Indigenous believe the time is right to lean more on the latter (courts) than the former (the act).

Because it's insane colonialist garbage that should have been gone last century.

He hasn't said if he wants it replaced with anything or what to replace it with.

He did make it clear that he doesn't like the paternalistic and colonial aspects of it. Plenty, if not most, of indigenous folks have always hated the government appointed "indian agents". People also hate how multiple, diverse indigenous groups are all boiled down to "Indian" that need to be "civilized" and protected by the benevolent overlords in the current act.

That's my read and understanding at least. It's outdated af.

I take it to mean "We still want the money but let's change the demeaning language", and I'm all for that.

When he comes up with a plan that actually moves the First Nations people's forward, he can go right ahead.

Just calling to abolish it without any protections moving forward, even if the exist ones suck, is not the better option. Dropping the act and just letting the chips fall where they may is a fucking bad idea.