Tobias' contract restricts flexibility this Summer too much. I think it's more likely that Danny would pursue Jabari.
I think this has become sort of the knee-jerk response about trades before the deadline.
If Ainge can consolidate some mid-level assets into a very good, young NBA player under contract for a number of years, he'll do it. That's exactly what he'd hope to achieve this summer anyway with said flexibility.
What he won't do is trade for a past-their-prime player under contract for next season or beyond who WON'T improve the team or help attract FAs this summer (read: Kevin Martin). Harris isn't in that category.