Niantic have announced the details for the Pokémon GO February 2021 Community Day which will feature Roselia. The original press release news article on Niantic's site had a Community Note about users feedback when it comes to which Pokémon appear during Community Day's but the note was quickly taken down off the site moments after its posting.

Roselia is the featured February Community Day Pokémon!

Trainers, Did you know that a Roselia’s flowers smell more pleasant the healthier it is? The scent is said to deeply relax people. This February’s Community Day is sure to be relaxing, then—because Roselia will be the featured Pokémon!

Date + Time
Sunday, February 7, 2021, from 11:00 a.m. to 5:00 p.m. local time

Features

• Roselia will be appearing more frequently in the wild. If you’re lucky, you may encounter a Shiny one!
• Evolve Roselia during the event or up to two hours afterward to get a Roserade that knows both the Charged Attack Weather Ball (Fire-type ) and the Fast Attack Bullet Seed.
• Take a few snapshots during Community Day for a surprise!
• Event-exclusive Timed Research will be available! By completing these Timed Research tasks, you’ll be able to earn Sinnoh Stones.
• There’ll be a special one-time-purchase Roselia Community Day Box available for 1,280 PokéCoins, featuring an Elite Fast TM, four Incense, four Super Incubators, and 30 Ultra Balls.
• For US$1 (or the equivalent pricing tier in your local currency), you’ll be able to access the Roselia Community Day–exclusive Special Research story, Stop and Smell the Roselia. Remember, Trainers—if you purchase a ticket for the Pokémon GO Tour: Kanto event by Wednesday, February 3, 2021, at 11:59 p.m. PST (GMT −8), you’ll get this Special Research story for free!
• Budew will be hatching from 2 km Eggs.

Stay tuned for when tickets for the Stop and Smell the Roselia Special Research story go live! Tickets are nonrefundable (subject to applicable law and the exceptions set forth in the Terms of Service). Please note that this Special Research will not include an in-game medal.

Bonuses

• 1/4 Hatch Distance when Eggs are placed into an Incubator during the event period
• Incense activated during the event will last for three hours

Community Note:
Trainers, we have heard your feedback when it comes to which Pokémon appear during Community Day. Stay tuned for announcements about which Pokémon you can expect to be featured during upcoming Community Days.

Please be aware of your surroundings and follow guidelines from local health authorities when playing Pokémon GO. Upcoming events are subject to change.

Source: https://pokemongolive.com/post/communityday-feb21/