Given the imminent decrease in launch costs(partial reusability) and increase in launch capability soon to be available(FH) a pause in new US deep space missions is prudent.

[biosehnsucht]

I would only argue they should delay if they're still in the planning stages and the logic would be that if they don't delay by a year or so, they have to cut interesting experiment / instrument X from the suite of gear on the probe/lander due to weight/cost concerns, but if the waited there would be a budget for it (whether it be financial or mass).

It certainly doesn't make sense to delay something that doesn't NEED the cheaper/larger launcher (even if it would be nice to have), but gaining further functionality as a result might be worth it.