A tip just posted to Weibo purports to have captured the housing for the Huawei P40's rear cameras. This component exhibits just 3 circular cut-outs, suggesting that the P30's successor will have this number of main shooters. A further leak indicates the presence of a P40 Lite, which may have a punch-hole display.
https://www.notebookcheck.net/No-periscope-lens-for-the-Huawei-P40-according-to-a-new-leak.449299.0.html
Well a separate camera with a separate bump can't be entirely ruled out either, it's happened before.