If population dense areas remain "television markets", then for the B1G to grow profits, they'll need to grow into populous regions. Delaney has demonstrated his willingness to grow the membership of the conference, one would assume primarily for monetary profit. The OP asked what's the endgame?
I don't have an answer to that, but expanding the southern footprint of the conference seems to make a good deal of sense.
I happen to agree with Tex in one regard, that expansion from the ACC presents more of a challenge to the Big 10 or B1G than the SEC.