Using the new NCBI Datasets platform, you can browse the collection of genomes associated with one or more taxa. For example, searching Pseudomonas aeruginosa returns 19,878 genomes as of 29 March 2023.
In the search filtering tab, they give the option to "Exclude atypical genomes". Applying this option to the previous search returns 19,737 genomes, implying that 141 genomes were discarded as atypical.
What criteria are they using to label genomes "atypical"? I've read the documentation for the NCBI Prokaryotic Genome Annotation Process, and my hunch is that atypical genomes are those that are annotated with atypical genes, though I'm not sure.