Is walking eevee 10 km as a buddy tricks still works ?

Yes it still works but only once, if you haven't used the name trick then you can still get another umbreon with changing the name

Some of the problems people have had:
- Not a buddy at time of evolution.
- Switching buddies partway through walking. Get 10 km, but not consecutively so not 2 candy.
- Walking during reduced distance event. Get two candies, but not walked 10 km.
- Lost GPS reception. Game doesn't know where you are, so doesn't know whether it is day or night and just randomly evolves.

Be that as it may, Vaporeon with Aqua Tail has probably been my most used Eeveelution in gym fights. Although not as much since the gym change and there are no longer multiple Rhydons stacked in every gym.

Not sure it matters but, when you click on your profile and then click on your buddy, if you click on "Walk with your buddy!" it takes you to the mon's page. I saw at least one post that suggested evolving your eevee buddy, after 10km & 2 candy, through that access to get espeon/umbreon.