It's possible, but I deem it likely things wouldn't have branched out too differently by that point. Khitomer happened before hostilities would have broken out between the Federation and Klingons and I don't think a colder relationship between the Federation and the Klingons are going to effect Klingon/Romulan relations much, that early on. Until Narendra III the Klingons would've viewed the Federation as another rival instead of an honorable neighbor as they did in the normal timeline. That wouldn't mean the Romulans would be any less inclined to strike Klingon targets.
You can argue yourself in a circle about how events would work themselves out if history is altered, as until we invent a way to alter time there's no tangible evidence, but in Trek the precedent is, even when things change... the smaller things stay mostly similar.