I doubt it. Given the mix of fleet Eastern have, it wouldn't make any sense to merge with them. If anything it would be a takeover by flybe not a merger. Flybe could easily see them off certain routes.
Eastern could continue to be a subsidiary of flybe, operating their aircraft on thinner flybe routes. What this offers flybe I have no idea as they could just avoid the market. Flybe have much more brand awareness than eastern, who currently appear to be completely lost and failing miserably in terms of performance.
Have a similar underside can't have any relation to a merger. Plus one is blue the other is purple.