Ya, as a direct replacement for the UPT and IFF T-38 only on a 3 to 5 buy ratio, hoping to cover the gap via reduced attrition. The T-1 will be around well into the 2030s.
Some of the more amusing calls I fielded as a T-1 Flt/CC were from my T-38 counterparts trying to poach my gunships/C-17s/AFSOC/etc in exchange for their E-3s and such. That's all well and good if it helps my guys, but the phone was quickly set to the "go fuck yourself" position when those guys tried to imply that because their students were flying the T-38 they were inherently better than my T-1 students and would have aced the T-1 program and finished ahead of my guys anyway.
The fact of the matter is it is a myth that doing well in T-6s is an automatic identifier of future performance. It is frequently a result of either prior flying experience, or being a faster learner within a given medium. I saw guys who aced T-6s, chose T-1s (to the wailing and gnashing of teeth of the people who though they should go 38s) and then finish bottom 3rd in the T-1. Conversely I saw guys finish dead last in their T-6 class, come across the street to me with an apology note pinned to their lapel, and knock T-1s out of the park.
So implying that students that track T-38s are inherently better than students that track T-1s is quantifiably bullshit. There most certainly are people who bottom feed the T-6, and then bottom feed the T-1, but there are also students who kill the T-6 and are gone from the T-38 before their first checkride. I'd be willing to bet those 38 washouts would have been T-1 washouts all the same. The T-1 and T-38 [programs aren't so different in terms of difficulty, it's just the nature of what is difficult. The T-38 is fast moving and demands precise and rapid decision making. The T-1 is complex, operates in a complex environment with limited to no outside decision making help (Sup, SOF, wingman, etc), and requires a lot of dynamic task management. The product of each program is different, but I wouldn't say one is better trained than the other.