Republicans appear to be telling Democrats, "If you raise taxes on corporations and top earners, we'll just cut them back when we regain power." As Jonathan Chait notes, this is a true statement even if Democrats don't raise taxes on corporations…
Republicans are going to cut taxes for rich people the next time they hold power, regardless of what Democrats do. Over the last three decades, Republicans have made clear that they believe the perfect response to a slowing economy, a rapidly growing economy, a budget deficit, a budget surplus, war, peace, high inflation, low inflation, or deadly pandemic is to give rich people a nice big tax cut. It's their religion.
So, yes, if Democrats raise taxes on the rich, then Republicans will cut taxes for the rich next time they gain power. For any X, the statement, "If X, then Republicans will cut taxes for the rich next time they gain power" is true.
There are a number of key issues that define the difference between the two major parties. This is a big one. And I'd be very surprised if any prominent Republican would deny it. Some of them would probably be very proud of it.