The smallest subnet you can create in an Azure VNet is /29 (for IPv4) - as far as the largest one, that's dependent on the maximum address space allowed for a single VNet is /16. This gives you the total of 65,536 total combinations of 0s and 1s - but you have to account for the 5 IP addresses which are reserved by the platform for every subnet in that VNet - so effectively the total number of IP addresses available in individual subnets within that VNet is always smaller.
In short, the MS Learn information you are referring to is either simply incorrect (not applicable to Azure VNets).
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hth
Marcin