I'd like to say that I really value the fact that each of Nokia dual-sim phone is a real Dual-SIM, i.e. has two slots for SIM cards and separate one for memory card. Please don't even think about making optional dual-SIMs!
I've never seen anyone who said that he's glad not having ability to use two SIMs and memory card at the same time.
Unfortunately the Nokia 8 has a hybrid SIM/microSD card slot, so it's already not a real dual-SIM phone like you suggest.
I fully agree with your request for 3 slots - two SIMs and one microSD card.
I note the Nokia 2 has proper dual SIM, not hybrid,
One of the reason I picked Nokia 5 but not Nokia 6 was it has dual sim slot and a dedicated SD card slot last year. Please HMD Global! we need dedicated SD card slot for upgrading memory.
I'm not sure why HMD and other smartphone manufacturers continue to think that dual-SIM is not wanted on flagship phones. I love tech, want the latest and greatest, but I have a life in two countries in Europe, so I have two SIMs. I don't want to carry around two phones, I want to carry only one phone, so I need a flagship phone with dual SIM.
AND an SD card slot. Come on HMD, I'm looking forward to the Nokia 9 being my "wishlist" phone :D