This strikes me as an incredibly short-sighted thing to do -- but not an unexpected one.
The area around the Caledonia Road Church is desolate and forbidding. Moving the Bus Depot there would only continue that atmosphere. The church itself, which should be something Glasgow is proud of, will continue to be nothing more than a traffic island -- until it eventually has a mysterious fire, a bus drives through it, or it simply falls down from neglect.
The sensible thing to do would be to keep the Bus Depot where it is -- by all means redevelop it, the area around it is pretty bad too.
Then have the shopping complex where Southside station is. Part of the condition of redevelopment should be that the church is renovated. That way the surrounding land may be more attractive to housing development. Especially, since on a good day you can actually walk to the city centre from there -- rather than commute from some lego-built suburb for 45 mins per day. It never ceases to amaze me that there's a mile-wide ring around the city centre that's pretty much derelict or dangerous, while external greenbelt is eaten up for commuters. I know that the inner city was once slum and had to be cleared -- but that's no reason why now, especially with traffic congestion, that this area cannot be full of housing again. By that I don't mean "luxury" flats, I mean good tenement-style buildings that ordinary, decent people who work in the city centre can afford.
Our beloved city fathers could also consider re-opening the railway line there -- or at least as much of it as possible. Light rail is fine. The remaining arches behind where St Enoch Station was could, perhaps, be developed into a small station again, or just use the car park adjacent, for something larger. Many stations in Germany are built into shopping centres, there's no reason why that won't work here too. I realize that that's not a small project, but it is the sort of thing that Glasgow absolutely has to do eventually. Why not sooner rather than later? Those lines should never have been closed in the first place.
It'll only help the Citizens Theatre too -- must be one of the hardest theatres in the country to get to -- navigate the complicated, badly-signed one-way system, or risk your life on the short walk from the Underground or bus.
However, I suspect that First Bus has many brown envelopes, and that they could be large -- so I guess the continued desolation and isolation of the Greek Thompson Church is absolutely inevitable.