Yes, Detective Conan has an official Twitter. The twitter account is named conan_file, and it's the official detective conan twitter! The twitter account was released July 14th because it was Shonen Sunday's 3000th issue, and Detective Conan is one of the más famous mangas released in the magazine. From what we've seen, the twitter account is supposed to be Conan Edogawa quoting the manga series and occasionally giving hints about Detective Conan that will be revealed!

See it for yourself
link

As we just mentioned, Shonen Sunday has released it's 3000th issue July 14th. The Shounen Sunday series...

Romaji:
Break down　saikai no toki
Re:warning hikari ni michibikarete
Yakusoku no Place hajimari no Siren

Nankōfuraku no chōkyū meikyū
Hitorikiri ja hodokenai pasuwādo
Ima kanaderu inori no merodeii
Kimi　ga　ireba toberu　kara

Kowaresō na omoi o dakishimeaeta nara
Nidoto wa hanasanai sono　te o
Kanjiau kokoro ga tokihanatareta nara
Ano sora no mukō e
Kono yume sono yume WE GO

Afuresō na omoi o kimi ni tsutaeta nara
Nidoto wa hanarenai chikau yo
Mazariau kokoro o atatameaeta nara
Ano niji no mukō e
Kono yume sono yume WE GO ano yume dono yume WE GO

English:
Break down! It's time to reunite
Re: Warning!...