@Ryan Plesz
There is no doubt if any of the discussed mergers go through it will have ramifications, but to what extent will depend on many variables, including how many employees relocate, can the state attract new major employment, and also what asset class you are invested in.
As an example, while GE is eventually moving to Boston from Fairfield, they are now transferring most of their employees to Norwalk for the next several years, so I don't think the impact will be immediate and if [big IF] CT can get other companies to fill some of their space it may not be a huge detrimental impact. But of course it could be too.
The asset class you're invested in will also matter: If you are invested in Class C properties there is a good chance that you will be less affected (but still impacted) than Class A and B rentals in the Greater Hartford area, yet if employment takes a big hit, it will likely hit all classes of rentals.
As @Michael Noto mentioned, there is going to be a risk everywhere that you invest. That is not to diminish your point, I do think it's a very valid concern - and something that concerns me in the overall Connecticut market due to it's unfriendly business practices - but just know that market risks will be everywhere.
As a side note, Cigna is in the process of being acquired by Anthem unless it is blocked; and Aetna is trying to acquire Humana (not be acquired). However, Aetna still may leave CT (here is a link to an article a few months back about that: http://www.courant.com/business/hc-aetna-annual-meeting-20160520-story.html)