That I'm no so sure about. What was part of Detroit's ruse was having 58 and 68 approach the ref together while 68 reported. 68 sounds like 58 so even if announced, the defense could get confused in the heat of the moment and think it was 58 having just seen 58 in front of the ref also. From what I remember, 58 and 68 lined up on opposite sides of the line, both on the end of the line until a TE covered up 58 just before the snap. Goff could then read the defensive coverage and go to plan B if necessary. Brilliant plan, the ref just didn't follow their own rule. That's the risk Detroit took.
The referee does two things when a player reports as eligible.
They announce it stadium-wide and they walk over to the defense and tell them specifically the number that is eligible.
That's the point so many people are missing. They assume it would "trick" the defense but the only way it would work if reported correctly would be if the defense completely blew the assignment, which would be no different than blowing any defensive assignment, not just one related to eligible receivers.
The truth is that it only worked because the referee told the defense the wrong player was eligible.
As I said, I am all for teams trying to find creative ways (aka: loopholes) in the rules to gain an advantage, but the NFL specifically focused on personnel trickery years ago which is why they started cracking down a lot more on too many players in the huddle, interrupting an offense ready to snap the ball to allow the defense time to adjust for offensive substitutions and of course handling non-eligible players reporting as eligible.
This is just one of those areas where the NFL rules are so strict that there is really no room to "trick" anyone.
The best you can hope for is a blown assignment by the defense and there are several ways teams try to make that happen every game.
The NFL has refined their rules to make success more about player skill and play execution than manipulation.
When a team is down near the goal line and/or going for 2 points, the defense is going to focus heavily on every eligible receiver.
If the Cowboys had been told the right number, then there would have been at least two defensive players whose assignment was to cover them, including one on the line and one in the secondary.
The referees announced the wrong number to both the stadium and the defense and that caused the Cowboys to focus on the wrong player which allowed the play to work.
Now, would it have worked if the referee announced the correct number? It's possible, but only for the same reason any conversion play works in the NFL which is usually due to blown assignments or bad execution by one or more defensive players.
As it is though, the Cowboys were told to guard the wrong player and they did guard the wrong player so it is not surprising at all that it worked to a player they were not covering.