Private chats aren't E2E. But anyhow, why do you think you were restricted based on specific keywords? And how does that restriction look like? Can you please check your access with @SpamBot ? Because in Telegram, if you PM someone, they have a big red button that'll block you and report you for spam - and Telegram often temporarily restricts accounts for reported unsolicited PMs.
Oh, and the title is misleading, there's no such thing done on the client side for sure.
