Saying the BOR approved construction is overstating it a bit as to where OU is at in this process. Funding for the stadium is still to be raised. Note this in the article:
“He (Joe C) said the next step for the construction and renovation of the facilities is to seek approval from the Board of Regents about a full-fledged funding plan. He didn't give any concrete dates for when the athletic department will return to the board but is hopeful that it could happen in the "very near future."