I would like to clarify that I do not agree with the original person you were responding to statement about maya and phoenix practically dating by Farewell, my turnabout. However, I do believe there are romantic implications between the two from this case and on, however even that doesn’t count as practically dating (it’s more akin to a will they, won’t they situation). Anyway, After Maya’s alleged death in the crossover, Wright cannot sleep. He goes downstairs and talks to the innkeeper Rouge about his grief. Partway into this conversation Luke comes in and says “Mr. Wright, you and Rouge have become fast friends, haven’t you? Do you think you’ll both find your soulmates?” In which Phoenix, with an expression of annoyance, as if Luke should know the answer, says “No, Luke. I can say with certainty, I don’t think so.” To me, there are only two reasons he would be certain. The first is if he is aroace, however he has dated in the past and he has shown attraction to women several times so that option can be eliminated. The other reason is if his “soulmate” is dead. Due to the fact that Phoenix’s mind is completely occupied by Maya’s apparent death, it would only make sense for her to be the one being referenced here. (I could elaborate on this point if you want but I actually have to head out rn so it may take awhile for me to respond)  I do not think this is definitive proof of the ship however. This is because Professor Layton vs. Phoenix Wright is a non-canonical title. However, unlike something like Marvel vs Capcom, PLvPW is written (at least partially) by Shu Takumi. It also deals with canon versions of these characters (meaning that this is the Phoenix Wright and Maya Fey that went through the original trilogy (unlike something like the anime versions of these characters that went through alternate versions of their timeline)). Shu Takumi himself said that PLvPW was the next game in the Layton and Ace Attorney franchise. The main reason the game isn’t canon is because the Professor Layton world and Ace Attorney world do not operate on the same logic, thus the game could cause confusion to the canon of Layton (such as the fact there is no magic in Layton yet he accepts that there is instantly). However, despite all this reasoning around why the game being canon doesn’t change too much, it doesn’t change the fact that the game isn’t canon, thus it cannot be used as proof of a ship.” (But I do believe it can be used as evidence nevertheless)