Post-op guy here. I do produce an "ejaculate" during and/or after masturbation, similar in consistency to cis guys' precum. Its basically the same fluid I produced pre-op as lubrication/"wetness" but because it doesn't have another outlet/use now that I've had vaginectomy, it just comes out of the tip. It's not like a forceful stream or anything, it's more of an ooze, again, like precum. And depending on how I'm sitting/laying after I'm done, it may dribble out on its own, or it may not come out until I pee.
As a note, in the phalloplasty circles/online groups I'm in, this is actually a common phenomenon. It won't happen without urethral lengthening for sure, but I'm not sure whether or not it would happen with the combination of no vaginectomy with urethral lengthening, since that's just not something we see as often (due to the increased risk of urethral complications).