The best thing that comes from this news is that the current mid-December signing window moves to the first week of December, clearly separating the Transfer Window with the HS Recruiting Period. This will allow coaching staffs to evaluate Transfer Window needs after setting the roster with "early" HS additions. This should lead to a cleaner evaluation process (i.e. HS kids with offers are less likely to get them pulled because of transfer additions, as coaches can more accurately forecast scholarship availability).
I'm a little less clear about what adding a June signing window actually does from a final roster perspective. In this past recruiting cycle, 85% of players signed in the December period (vs. 15% in February period), so the de-facto national signing day has already become December. With these new rules, my guess is that the ~85% of kids that sign in December will now be spread across both the June and December signing periods. This benefits coaches not having to worry about some kids flip flopping in-season. However, as Gerry mentioned today on OTF, most Texas coaches don't recruit during the season anyways, so I'm not sure if this actually saves them any time - but I get the mental relief of knowing a kid is officially signed.
In the end, I can see this change benefiting college programs that end up underachieving in season, because the players who signed in June would technically still be committed to that school (assuming there is an ironclad structure to prevent easy de-commitments). However, that is likely a one-time benefit since if you are constantly underachieving, you aren't going to be getting top recruits. For a program that is on the rise like Texas, I don't currently expect the new structure to lead to a materially better roster or recruiting advantage for Texas.