I'm not sure what you expect. You're describing how most strikes happen. Unions have contracts that they follow. Strikes only tend to occur when the the company violates the contract or during the contract negotiation period. The UAW is asking that a bunch of unions align their contract expiration dates. Then the unions will make demands for new contracts. If the capitalists comply to the demands, then a strike won't happen. If the capitalist don't comply, then the strike will happen. The purpose of a general strike is greater bargaining power for the unions. The general strike is a threat. The goal is to receive concessions.

Almost every strike in the US is announced and voted on before it happens. Wildcat strikes (unauthorized strikes) were made illegal in the US in 1935.