The concept of a multi-speed EU has been around for decades, originally being born as a solution to prospect of EU expansion eastward after the Cold War period. This new proposal from Germany's Finance Minister includes Germany, France, Poland, Spain, Italy and the Netherlands.
With the growing rifts in the EU, a dismal proxy war against the EU's chosen mortal enemy, and the US's open aggression towards European vassals, circumstances are different now from the 90's.
While this is primarily pitched as a move for financial stability and growth, there is of course a defense aspect as well, with Germany's Finance Minister saying, defence should be embedded as a priority in the next EU multiannual budget.
This could be a move for the dominant EU powers to marginalize less powerful countries, and continue forcing Europe on the war march even as the situation in Ukraine looks worse and worse.