I stand by my recommendation to wait two weeks and it has only been one week since the announcement. We are starting to see the big vendors react. In another week, you will almost certainly be able to mostly painlessly move your basic services over to a node.js/MongoDB system somewhere. Your management, IMO, should not be freaking out. Here's an Internet Chill Pill to give them. They're welcome.
There are dozens of push notification vendors. Every Cloud Code module appears to exist for node.js too. What else do you need to keep running? According to early reports, you can migrate your data, the important thing, quite easily. Parse Server, as a surprise to me, is actually being updated by Facebook staff. I've provided fixes to the engineers committing to the code base myself and they are competent and supportive.
IOW, you can be back to your baseline rather quickly. Then, and only then, would I start to make broader plans. IMO, running on Parse Server is a short term solution. It will need maintenance. Other open source efforts always have a lead team. In Parse Server's case, the team is probably evaporating as I write. I think Facebook will apply the golden handcuff solution until July 28th, then staff are on to other projects or the startup Valley winds.
What would change this scenario? Basically, Parse Server probably has to be submitted to something like Apache or whatever is the home for node.js open source projects. Folks from the service vendors, such as Heroku and MongoLab and others will have to step up to support this orphan technology and provide industry wide governance. It might happen.
In my case, I am planning to execute the above plan. Move to MongoLab by April 28th and Heroku by July 28th, per Facebook's recommendation. I am looking at other solutions for my long term development. At this time I have not chosen a new path.