Of course there is a chance, but I think it would be hugely detrimental to their interests. It will be extremely foolish of them, because they will gain nothing from it. I just don't think they're that stupid.
Should Israel be attacked, it will definitely retaliate, but I don't think they will attack with the intent of escalating the situation. They will probably symbolically target the missle launchers and other strategic military locations to save face that they "did something". They do not want to get dragged into this.
I also do not expect Iran to get involved in this scenario. They will make some noises like they love to do, but that will be it. The way I see it, the threats the Syrians are making is just talk. I may be wrong, but this is my perspective.
I'm more concerned with what Hizbollah would do in this scenario.