Skillspeed/Spellspeed the new META?

[Bonbori]

It does not. Heat Blast is already at the minimum GCD of 1.5. At most you can fit 5 into a Hypercharge and you need to weave in at least 1 GR and 1 Ricochet to avoid overcapping. Even if it was possible to reduce it even more, I can't imagine a sixth Heat Blast would be possible without running into either overcapping, clipping or simply lag issues.
As for 1-2-3 weaving, while, yes, single weaving might be viable in isolation, the reason double-weaving is done is to fit as much damage as possible inside of party burst windows, as well as to dump the stacks in preparation for the next Hypercharge.
And regarding resource generation, it really doesn't shave enough recast time for that to matter. Due to diminishing returns, no amount of SKS will allow you to fit additional Air Anchors inside a standard ~8-minute fight. You'd be lucky to get one extra towards the end (and that is unlikely to amount to an extra Queen).
Plus, keep in mind that every SKS materia would replace a Crit/DH/Det materia that a MCH would otherwise use. This means that on average each 1-2-3 combo, each Drill, each Air Anchor, each Heat Blast, Ricochet/Gauss Round, would do less damage than expected. Those losses would add up over time and any extra casts would have to make up for lost damage rather than multiply it.

[Orbus]

while single weaving might be viable in isolation, the reason it's done is to fit as much damage as possible inside of party burst windows.

Let's be real here, this only applies in highly coordinated groups which is neither necessary nor likely outside of extreme content.
And I don't know how you equate quicker hypercharges, which is when the job deals the most damage, to doing less damage.
It doesn't matter that skill speed doesn't reduce the recast of heat blast because faster heat build up indirectly buffs heat blast by putting you in hypercharge more often, which also indirectly buffs ricochet and gauss round for the same reason.
220+150 potency every 1.5 seconds five times, that blows everything else in the kit away by a landslide and that includes reassemble drill/air anchor.

Look, I'm no expert at the job, but you can't just ignore the indirect effect skillspeed has on most of the kit just because it doesn't directly lower heatblast's coowldown.