Var det ett misstag att X-Wings i The Force Awakens väntade i hyperspace?

Kort sagt, ja. De DID (1) vänta i lightpeed som du noterade, och (2) kommuniceras i lightpeed, som bekräftas av WGA script. Och det har inte någonsin setts tidigare i Star Wars; och # 2 har ännu inte förklarats eller retconned så långt jag kunde hitta.

Först, för att bekräfta dina observationer från WGA-skriptet:

OFFICER
General, their shields are down!
C-3PO
Thank the Maker!
LEIA
Han did it! Send them in!
ADMIRAL STATURA
Give Poe full authorization to attack.
REAR ADMIRAL GULCH
Black Leader, go to sub-lights. On your call.
INT. X-WING - DAY
At LIGHTSPEED, Poe pilots:
POE
Roger, base -- red squad, blue squad, take my lead.
INT. X-WING - DAY
Nien Nunb pilots, acknowledges order in alien language. INT. X-WING - DAY
Another pilot, ZOLO ZIFF.
YOLO ZIFF
Dropping out of lightspeed.
EXT. SPACE/STARKILLER BASE - DAY
With CONCUSSIVE BLASTS, the X-WINGS APPEAR and ROAR PAST CAMERA toward the Starkiller Base planet!

Fosterförkortning (som vanligt) är lite annorlunda och mer sammanhängande, men tar inte upp några av problemen:

In another command and control center, on another planet in another system, there was a spontaneous outburst of excitement, followed by a hurried response. “General,” the head tech cried out, “their shields are down!”
“Oh my.” Threepio leaned toward the relevant console. “So they are!”
“You were right,” Leia said to Statura. “Send them in!”
“Give Poe full authorization to attack,” Ackbar informed a junior officer stationed at another console. “All available ships, no hesitation. He knows he’s not likely to get a second opportunity.”
“Black Leader,” the officer declared to the pickup that would send out the command via the identical set of relays, “go to sublight. Attack, attack. On your call.”

It was the order Poe had been waiting for. While unsure it would come, he had nevertheless run over the strike schematics in his head a dozen times. Timing was critical. Having plotted the vector to the planet that was home to the Order’s Starkiller Base as an arc, both to deceive any long-range sensors as well as to delay arrival and emergence from lightspeed, now they could revise the route and head straight for the target.

“Roger, base.” Hitting the controls necessary to alter course within a lightspeed run, Poe addressed the rest of his flight. “Red squad, blue squad—follow my lead.” At his touch, their revised vector entered the flight computer of every ship in every squadron, and the X-wings promptly adjusted as a single unit.

Observera att X-Wing-framväxten i novelleringen klart inte var ögonblicklig - efter att skölden föll ner, hade Kylo Ren och hans lag en chans att undersöka Falken och han lutade sig lugnt i Falcons cockpit efter det. Endast då ...

His deliberation was interrupted by a thunderous roar as squadrons of X-wings dropped from the sky, rocketing toward the hexagon-shaped bulk of the containment field and oscillation control system. Rising from the seat, he rushed out in time to see the Resistance fighters drop toward the massive structure—and begin their bombing runs.

Så om du tar noveliseringen som en retcon:

• Kämparna väntade inte kvar på ljussteg. Istället låg de på en lång bågskurs mot StarKiller, i grunden ett typiskt cirkulationsmönster över målet / aifielden.

• De mottog beställningarna i lightpeed (så långt jag vet, bryter mot befintlig tidigare kanon)

• Sedan ändrade de - medan de fortfarande var i lightpeed - kursen för att gå direkt till Starkiller.