Upvote:5
I wanted to know if it necessarily means my application is approved
No, this doesn't mean that your visa is approved, it can be either way, and you'll have to submit and wait for the passport to see the result of the application.
Visa decisions are confidential and delivered in sealed envelopes, nobody at the processing middleman (here TLScontact) know your application status, only the UK Home Office currently knows about your case
Relaying @Traveller, this is what TLSContact says:
Once the decision of your visa application has been made by the UK Visas and Immigration, you will be notified by email, and then you need to provide your passport to the Visa Application Centre (by post or in person). If you donβt provide your passport within the determined timeframe, your visa application will be refused; Once received, we aim to complete the application and return your passport as soon as possible