A brick by brick rebuild was was only possible with the Carlton Tavern, because the local pressure group suspected that the developers were going to pull a stunt, and had Historic England photograph and document every inch of the pub right down to taking plaster casts of all of the tiling, so a detailed record was available for the rebuild. If that hasn't been done for TCH, a facsimile rebuild will probably be considered impossible.
As things stand, jail time is unlikely. Even if it was shown to be arson, proving who was responsible to a degree likely to result in convictions is a whole different matter unless someone comes forward and grasses them. That would probably have to be the match-lighter, and he'd end up doing time too. The demolition of the building is nothing to do with the police, so any remedies to this are likely to be in the hands of the planners rather than the police/courts. The best you can probably hope for is an order to rebuild a pub, rescinding of any permissions granted or pending, and a massive skidmark on these people that'll hopefully affect any future applications they make.
There's also some small comfort to be taken in the fact that Mr and Mrs Taylor are highly likely to be be shitting their pants at the moment and will be for quite some time.