well, the only "watch out for the blast" warnings I remember were from FS1 in reference to the Zod freighters in that cargo mission and the powerful Shivan bombs, back when the player still didn't have shields and shockwaves did do an insane amount of damage (and w.r.t. the Faustus cruisers with the huge blast, in which case they still do).
Would be an interesting change, though- It'd be nice to see a battlefield where the epic (and epic-looking, now) capship explosions actually felt powerful. The only time they affect us at all now are when we're in bombers and stay ridiculously close to a destroyer as it's going down.