I'm cautiously optimistic (less optimistic than ESPN) because efficiency doesn't always scale nicely with usage. Haliburton was the 3rd most efficient offensive player last year at an ORtg of 136.8, but only at at 10.1% usage. I think he needs to up his usage up to around 20% or more to be the leader that we expect him to be. I took at look at the last two years of ORtg and Usage data to try to find a couple high efficiency/low usage to high usage examples, but didn't find many (though I stopped about 25 players in sorting from highest ORtg). Probably the closest example I found was Skyler Flatten at SDSU, who had an ORtg of 127.0 at 13.7% usage in 2017-18 and went to 118.5 ORtg 20.0% usage in 2018-19, which is almost equivalent (just speaking in terms of ORtg and Usage) to Michael Jacobsen last year. I think Haliburton will be above 118 ORtg this year, but I'm thinking more around 120-122 ORtg, which is still pretty darn good but I'm not sure it's 12th best player in the country good.
That is some very nice research. Thank you.
Check out Monté Morris...

His efficiency stayed about the same his whole career (around 120-125) yet his usage went from 12.6% as a freshman up to 23.8% as a senior, rising roughly 3-4% per season.
If Tyrese can basically be Monté's junior year -- as you said, a usage around 20% with efficiency in the 125ish range -- then he will be having a great year. And yes, I know that is higher than you were hoping. Just going from 118 to 125 is a lot of efficiency gain. Then again, as much as we love him, Monté Morris was never an all-American or considered the twelfth best player in the country, so it might have to be even better if he is going to hit that level of acclaim.
I still think he can do it, but we are talking the edges of possibility here. If Tyrese is as good as that list implies, he is going to be a lottery pick and we will win a lot of games.