I’ve been seeing a lot of names ending in -yn the past decade (mostly for girls, but sometimes also for boys). In [name_f]English[/name_f], words don’t usually end with -yn, except for proper nouns (Brooklyn and some -lyn names were mostly it before the 80s or so) What cases of -yn endings have you seen? [name_f]Do[/name_f] you like any names with -yn spellings?
I see -yn endings a lot. Mostly for girls like you said. [name_f]Ashlyn[/name_f], [name_u]Brooklyn[/name_u], Lakelyn… for boys I think it’s mostly creative spellings. Like [name_f]Lakyn[/name_f], or Aedyn. I’m not a fan of creative spellings but I do like some -yn names. For example, boys names for girls. [name_u]Carson[/name_u] on a boy I like spelled like this. However, for a girl I may prefer [name_u]Carsyn[/name_u]. It seems more feminine sometimes to change the ending to a y. I don’t necessarily like the name [name_u]Carson[/name_u] for a girl, this is just an example.
I like [name_f]Eowyn[/name_f]. 
That’s not really the style you’re talking about though. So, if we’re talking millenial names, I think [name_f]Ashlyn[/name_f] is pretty sweet. Otherwise, though, -yn names just aren’t really my style, personally.
[name_f]Katelyn[/name_f] / [name_f]Kaitlyn[/name_f] comes to mind. Also [name_u]Devyn[/name_u], [name_u]Jailyn[/name_u] / [name_u]Jalyn[/name_u], [name_f]Maryn[/name_f], [name_f]Emmalyn[/name_f], [name_f]Carolyn[/name_f], [name_f]Karyn[/name_f], and [name_f]Tamsyn[/name_f].
I’m not usually a fan of -yn names. It’s not because they end in -yn, but more because they happen not to be my style. I do think it’s fun that they’re girls’ names that end in consonants! I love that.
The “yn” ending is an interesting one!
Names like [name_f]Ashlyn[/name_f] and [name_f]Jessalyn[/name_f] do give strong 80’s/90’s vibes.
Names like [name_f]Gwendolyn[/name_f] and [name_f]Eowyn[/name_f] give really medieval/fantasy/fairytale vibes.
I would still consider names like [name_f]Katelyn[/name_f] or [name_u]Evelyn[/name_u].
I don’t especially like using “yn” instead of a more traditional “on”, “an”, “en”, etc. like [name_u]Londyn[/name_u] or [name_u]Camryn[/name_u].
[name_f]My[/name_f] little niece was named [name_u]Wynn[/name_u] 
I like a lot of -yn names! I’m not sure I love any enough to use them in real life, but I have plenty on my list. [name_f]My[/name_f] favorites are [name_u]Brooklyn[/name_u], [name_f]Gracelyn[/name_f], [name_f]Carolyn[/name_f], [name_f]Lauryn[/name_f], and [name_f]Kaitlyn[/name_f]. I also like [name_f]Avalynn[/name_f] with two Ns.
I think part of the trend is that the Y is seen to make unisex names more feminine (like [name_f]Emersyn[/name_f], [name_u]Devyn[/name_u], [name_u]Carsyn[/name_u], [name_u]Camryn[/name_u], etc). Also -lyn endings in general are pretty trendy right now.