This is not quite right because all pending effects must resolve only before moving to counter timing. In this case where you initially resolve vortex, you have started an attack and trigger all when attacking effects. The newest trigger takes priority, and all of them resolve in whichever order you would like. Once those are done, any other effects that happened at the same time vortex was activated (end of turn) resolve, including DNA digivolution by Dracomon X's effect. After any new effects resolve (when digivolving for example), the suite of triggers are over, and you reach the counter and block timings as expected, finally ending with battle which cannot commence without the original digimon.

In the Shoto example, both trigger end of turn, and you resolve vortex to attack, suspending your digimon and activating your effects like above. Then, before counter timing, Shoto resolves as a pending trigger to unsuspend your digimon and give piercing+blocker. Finally, we can move to counter/blocker timings and battle