Denizens of the early 2000s internet will likely have fond memories of Yahoo Messenger, but the outdated service has seemingly served its purpose, and Verizon's Oath will be shutting it down on July 17, i.e. its servers will go down and you'll no longer be able to use it. The official app will be pulled from all outlets on all platforms as well. If you have any old buddies you need to exchange phone numbers or Facebook links with, you'll need to download the app from somewhere before that time in order to do those things, if you don't already have it. Even if you have the app, once the service shuts down, all data on the servers will be gone. Yahoo IDs will not be affected, so you can still use services like Yahoo Mail. Users will be able to download old chat logs using a special downloader found through the source link for the next six months.
This change does not mean that Yahoo is pulling out of the chat app world entirely. On the contrary, the company is planning to redouble its efforts with a more modern service, currently in closed beta testing under the name Yahoo Squirrel. The app is said to be focused on group messaging, but that's about all that Yahoo is apt to say at the moment. Anybody interested in signing up for the beta can apply through the source link.
It is worth noting that this change could have something to do with Verizon's purchase of the company and subsequent implementation thereof into its Oath property; the late '90s and early 2000s internet users with nostalgia for Yahoo Messenger's glory days will probably also remember AOL Instant Messenger or AIM, America Online's chat service that shut down back in 2017, not all that long ago. Verizon bought up AOL in June of 2015, and scooped up Yahoo last year. On the other hand, Yahoo had been in a steady decline for a good while before Verizon bought it, despite former CEO Marissa Mayer's best efforts to revitalize the company with moonshot-like initiatives and a hard push for fresh ideas.