Because of site conditions and the required ground work for the NE corner, if they are ever thinking of doing anything on the north end of the east side, they could do site work in preparation for a future structure there.
Is it possible that they could, hypothetically, build an indoor facility over there? sure. it's possible. it's possible they could implode the bram and build one there too.
You said you "bet they are looking into moving the indoor facility to the NE corner of the stadium." I'm telling you they aren't.