If your aircraft had super-dooper LO capabilities that covered the entire RF threat spectrum then the need for a high tech DRFM jammer is not that great.
If you are limited by the laws of physics then an all-aspect DRFM jammer could be handy.
If you have any concerns that the mere existence of LO aircraft around the globe may drive threat system designers to use different bits of the RF spectrum sometime in the next few decades, then you need to have the next bit of the countermeasures cycle ready - and in your weight growth and signature budget.