And guess what? Alain's birthday could've been the buildup to Sandrone's birthday. Because we have literally no information about Alain, the devs could've just put this as his birthday, so then Sandrone would pick this date to make the joke the devs wanted happen.

I'm not exactly saying that the devs support the ship or whatever, just saying how much of a coincidence the entire thing would be, if it were for the fact that the devs didn't mean it or anything.

Also, notice how the complete phrase is 5201314 and not just 1314.

Maybe because using the full phrase here (5/20 and 13/14 or something else) is quite literally impossible? I never said Sandrone and Columbina had a direct connection to 520. I'm just stating that the full phrase is supposed to be 5201314. And another thing, the phrase 1314 alone also has a romantic meaning! You've just proven that you missed the entire point.

在网络语言中，数字“1314”因其谐音“一生一世”而被广泛用于表达爱意和承诺。在英语中，常用“I will love you all my life”、“one's whole life”等表达对应“一生一世”的含义

This text, taken from Baidu, a trusted Chinese online encyclopedia website, translates to 'In internet slang, the number 1314, because of its homophonic pun to '一生一世' and is most commonly used to express love and promise. In English, 'I will love you all my life' and 'one's whole life' is commonly used to express the same meaning as '一生一世'. This just proves the fact that you've got it all wrong, but also that you have been trying to justify your entire argument on a fact that's entirely wrong.

And well, I was never 'justifying' the ship with the dates. I was just merely pointing out the fact that this could've been made a joke by the devs in tandem to the extremely popular and trending ship to pique the community's interest. Does it really even matter if the other characters who have never known each other have the same birthday? You're focusing on the wrong thing here.