Companies change their own rules all the time.
I was once covered by Scotts benefits but they changed my status from permanent to temporary and then to seasonal and decided I'm no longer covered.
It sucks but it's legal.
One of those right things is not to change the rules after the game has begun. Another is not doing what they did to you.
One of the things I have learned over the years is that the corporate culture is at least as important as what you make for building a successful company. The thought process behind this move is troubling.
If I had any funds invested with Scott I would be pulling them about now.