Buddy attracting same species?

Absolutely did not work for my pikachu. Although I assigned charmander and caught one in a place I haven't seen any before... But that was just like, one charmander, and I walked 10km with him today.

Although, this seems more like just a hell of a coincidence, since this spawns would apply to anyone around you. Maybe try walking with a friend and check if he also gets to catch those gastlys, or if they spawn to you like in a incense (what I think it's highly unlikely).

Also, after the "appraisals update", some "rare" pokemon began to spawn more frequently in places they once didn't spawn before

Edit: A couple of minutes ago, a charmander just appeared where I work. Never seen one here before, even after the "appraisals update".

I think you're right, I'm level 26 and before today I'd only ever seen three Exeggcutes in the wild. This morning I made one of them my buddy and now, ~12 hours later, I've caught two more.

So I'm just gonna float this theory, but what are the odds that Ditto shows up in the guise of your buddy Pokemon?

When i first saw this post i thought it was ridiculous. Then i thought about it, and realized when i had Graveler as my buddy (only needed 1 candy to evolve to Golem) i ran into a wild Geodude. Then, i made Kadabra my buddy as I needed about 10 candy to get Alakazam. I caught an Abra not long after. I know these are both not super rare, but still would be a strange coincidence. Note: I did also walk 5k with Snorlax to get a candy and didn't have one pop up, but then again, how often do you run into a wild Snorlax. I hope more people post on this topic, as I would like to hear more.

You might be right indeed! In my case instead of capturing the pokemon it, I hatched it!
I've assigned sandshrew and hatched immediately one which allowed me to finally evolve him.
Then changed and assigned magikarp and the next two 2km eggs hatched twice magikarp. Coincidence or not, I do not know yet but it would be good to figure it out wiht help of other players...

TreeHead and I are up to 31 km and I haven't seen or hatched a single one. I'm thinking this isn't a thing.

I've had the same experience first with ponyta then tentacool then rydon then tauros. Each time I either only needed one candie to evolve or power up. each time I encountered the same type both using incense and hatching eggs. as soon as I got my first buddy candy I would start catching or hatching that type. Previously I had only hatched these types. I think buddies attract like types for incense and eggs.

Update 10/06/2016 changed buddy to Growlithe had 10 candies. after I got 1 buddy candy the next egg to hatch was a growilthe. I think eggs,incense and buddy are connected .After I get my growlithe evolved I will try it with eggsecutor.