KEGG ribosomal gene found in metatranscriptome despite removing rRNA sequences

Question

[kmat]

I am conducting metatranscriptome analysis of human feces. I used SortMeRNA to remove rRNA sequences before assembly and then get predict gene sequences from the contigs. However, when I obtain KEGG KO annotations for the predicted gene sequences using diamond blastp, not a few sequences were associated with "ribosome". Additionally, there are many reads mapped to these sequences, resulting in a high representation of ribosome genes in the "gene composition" of the metatranscriptomes.

Is this occurs commonly? Should I consider excluding predicted genes with "Ribosome" when I get gene compositions as well as rRNA sequence removal by sortmerna?

Thanks.