I've realised that it all makes sense when you piece it together. The original timeline I mean, (the one where Barry's mother never died). On the last episode of season 1 we overhear Eddie mention the power of coincidence to Iris, when we dig deeper we realise the thing that brought them together technically was the mugger who snatched Iris' laptop. In the original timeline the particle accelerator wasn't unleashed until 2020 which means there wouldn't have been a mugger in order for Eddie and Iris to meet, (meaning "West-Allen" would be a thing in the future). Eddie also mentioned that he was supposed to date a girl that night, however when you think about it, those events prevented him from going out with this unknown person.... Maybe this other person is actually Eobard's great great great great grandmother from the original timeline. Therefore, being the reason with Eobard preventing Eddie's originally intended proposal to Iris in the current timeline.