As the article notes: this removal was not carried out under the controversial scheme. The man in question made a claim for asylum which failed. It would be illegal for him to stay in the UK. The controversial Rwanda scheme, however, aims to move people whose asylum claims have not yet been processed to Rwanda and have the claims processed by Rwanda.
Every year, a number of migrants are removed from the UK, some because asylum claims have failed, some because they over stayed after being granted a limited permission to stay, some because they committed a crime. I used to represent the Home Office in Court challenges to such removals (most of the cases I did involved criminals). Media sometimes suggest that the UK had or has an open door immigration policy, but the reality is that immigration is controlled. Whether the type and extent of control is set correctly is of course a subject of political debate.