Things like this aren't anything new. It'd be very foolish (and surprising) for a union to actively encourage its members to act in violation of the Railway Labor Act; they can't force individual members to make choices regarding voluntary flying. Defining changes in the "status quo" gets pretty subjective.
With the internet and various av forums, pilots can "chat" among themselves, exchange opinions and make individual, personal decisions.
This is Delta's go at it in 2000:
Delta Seeks Court Order Forcing Pilot Overtime - ABC News