I may be mis-reading what a partition looks like on nvme. if nvme0n1 is the whole device, then you probably want a partition. I You can run it without a partition but there have been some events as Pascal notes that may be because there is an empty/broken GPT partition on the device and the bios/EFI "fixes" it, overwriting some data. The original report showed that on nvme0n1p1 there as appeared to be a gpt partition table.
