The Wuhan lab being specialized in bat viruses means very little.
For one thing, this is a classic example of correlation != causation. Let’s say you had a shark attack on some beach and there was a team researching shark attack located right in that area. Would you then conclude that the team engineered the shark attack? The simple reality is that the most likely reason the team studying shark attacks is located in that region is simply because that region either has a history of shark attacks or even if it doesn’t have a history, is likely to have shark attacks. That’s why a team studying shark attacks would decide to locate themselves there.
The same is true here. Wuhan hosts a bat virology research institute because bat viruses are a higher risk here than in most places.
The other factor is that there is probably an infinite number of things that could look suspicious if there is such a disaster. It could be the presence of a bat focused research institute. It could be a conference that was held out there in the past few months. It could be a scientist from that region predicting a bat virus a few weeks before. It could be a district updating its pandemic protection plans in the weeks before. Etc.
The odds of any specific one of them happening are extremely low and would rightly make one suspicious. But the odds of at least one of the infinite suspicious things being true is almost 100%. And that’s probably all there is to it here. The presence of the bat research is just the 1 of many suspicious things that just happens to be true.
That being said, I think the strongest explanation is that Wuhan was considered a likely source of bat virus infections and that’s why the research was focused there.