http://www.geni.com/tr8n/phrases?section_key=&search={first_use...
There is another set of similar messages, with a more logical construction;
http://www.geni.com/tr8n/phrases?section_key=&search={first_use...
Should the first set be removed?
From the look of it, the first phrase is for when {first_user}=YOU, but it's *really* awkward English. The verb should be in second person plural form, if this is relevant.
I would be more in favour of something like "You and {second_user} celebrate your anniversary...". But the {first_user} token becomes a link to your profile which would be lost by removing the token.
I actually see the use for this now.....what could be more embarrasing (& source to endless pillorying), than forgetting your own anniversary....good one !
I will assume you are right and re-write this to something along the lines of your suggestion (the you-user will probably be able to find their way onto Geni without the link...).
...unless we are talking about this one;
http://www.geni.com/tr8n/phrases/view?translation_key_id=227920
Spoiler - Warning; Humour attempt coming up;
"Due to the risk of senility at your age, Geni is taking the liberty of reminding you that {second_user} will be expecting some kind of attention on or about {date} relating to your <Anniversary text>. You have been warned!".
On a more serious note, here is my suggestion at the moment;
"{second_user} and you will celebrate your <anniversary text> {on_date}."