I can't see HISD holding on to the land. It's become too valuable. I think they will sell it, just like they did when they sold the land and facilities of the old High School for Law Enforcement and Criminal Justice to St. Thomas High School for $60MM. Of course, that situation was a little different because acquiring that land was critical if STHS wanted to further expand its footprint, so their bid was considerably higher than any of those submitted by the competing bidders. But the land HSPVA sits on should unquestionably fetch a premium, as properties of comparable size just don't become available very often in the heart of Montrose.
The courthouse extension is the only thing that makes sense in this taxpayer boondoggle of a plan. The lack of access to the courthouse was a glaring oversite that I mentioned over three years ago in the Metro Rail East End/Southeast Line Downtown Construction pics and updates Thread. Also, I'm not sure why you think the CoH courthouse might be relocated or demolished? Absolutely zero chance for funding of a new a courthouse anytime soon.