I think it's a consideration at the trade deadline, not a priority. Certainly JT's injury (and declining performance) should be a wake-up call. It won't be that hard to bring someone else in, I just don't think it will be someone we enjoy watching or would want starting in October either.
Clearly Stubbs' current OPS is not acceptable. But he plays so little that just one or two good games over the next month would bring him to the level of most back-up catchers in the league. 30 catchers in MLB are <.600 OPS and 30 are >700 OPS (O'Hoppe happens to be #30), with 10 in between.
I was surprised they didn't go after Austin Nola, but guess what, he stinks too. Garcia is probably better than him.