TORONTO — Y Combinator is no longer investing in Canadian startups, forcing firms that want to join the Silicon Valley accelerator to reincorporate, likely in the U.S., The Logic has learned. YC, which is based in San Francisco, now only backs firms registered in the U.S., Cayman Islands or Singapore, according to its standard deal terms. Startups incorporated elsewhere must “flip” their structure so that their home-nation entity becomes a subsidiary of a new parent company in one of those three...