The roleplay is slightly less active due to Classic but it doesn’t affect the overall roleplay except that few guilds likely suffer slightly with events and so on.
Cities and zones are still very active due to the overall activity.
You can find roleplay 24/7 and every day if you just know where to look.
As stated above that it isn’t that hard to find roleplay if you just know where to look. There are plenty of discord communities and in-game channels and it is also a good idea to join a guild too but of course not a must.
Orgrimmar/Stormwind is the usual safe places to go to find random roleplay but if you want you can also look out for different zones on Alliance that can be Feralas, Duskwood and so on.
Argent Dawn have everything from trash RP in Goldshire to very good quality roleplay.
Due to Argent Dawn is a large server there are more of both as well.
You shouldn’t have any issues finding some quality roleplay both through random RP but also by joining a guild/community.
I mean of course there are those who love to write extremely large and detailed emotes and that is fine.
I just recommend to try to read the situation and adjust it to that.
Here’s a small list of addons that I use that I find useful for roleplay.
https://www.curseforge.com/wow/addons/cross-rp
This addon adds a number of powerful features to provide a smooth cross-faction roleplay experience!
https://www.curseforge.com/wow/addons/emote-splitter
Emote Splitter removes the character limit from your chatbox and lets you paste or type as much text as you want. It’s designed for roleplayers who like to type a lot, but is totally useful for other everyday use if you just want to send a long message. Normally you can only send chat messages up to 255 characters long. Any message that exceeds this limit is split up into multiple pieces and sent one by one.
https://www.curseforge.com/wow/addons/musician
Hear and play music with nearby players. For the first time in World of Warcraft, your character can literally become a bard!
https://www.curseforge.com/wow/addons/tongues
It allows languages, dialects, affects on outgoing messages.
It allows filters on incoming and outgoing messages.
It has Lore-style Interpreters.
It provides the ability to Mass Translate for: targetted player, translators (people added to the user’s translator list),party,guild, raid, officer, battleground, raid warning/alert.
Auto-translation of other Tongues users’ say, yell, party, guild, officer, raid, battleground and raid warning/alert messages.
Uses Blizzard languages when it can (ie Orcs speaking Gutterspeak will not be understood by Undead unless the listener has Tongues, Undead speaking Gutterspeak will be understood if both they listener have Tongues.)
Provide a quick select for picking which language to speak. (So you don’t have to open up the menu every time.)
Automatic Language learning (different languages have different difficulties for difficult factions, races, and classes.)
Allows you to speak for controlable pets with /petspeak or /ps
As you can see by the other posts there are plenty of guilds, communities and events based on both Horde and Alliance, with focus on all the different elves too.