No. The Linux kernel has two APIs, and has had since before systemd even existed. ifconfig uses the ioctl() API, which presents the concept of alias IP addresses in one way. ip uses the netlink API, which presents the concept of multiple IP addresses per interface in a different way. M. Siebenmann did include this point.
I think they are fundamentally different things. Correct me if Iām wrong, but I think a netlink alias is just an additional address and an old-school alias is more like a virtual interface.
* https://sourceforge.net/p/net-tools/bugs/12/
* https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=359676