Not particularly. In a sense larger, established companies are always looking at startups for market verification; the startups that succeed are the ones that can out-pace the established companies.

In addition, there are market dynamics that preclude any of the larger players truly building a platform for interoperability. See for example the recent Google/Microsoft turf wars, that Mailbox only supports attachments from Dropbox, iOS native composer only works with Mail and not gmail, etc.