I think Sizzle-Chest is just saying vanadium, aluminum, and manganese are
alloying elements in VALite, not that it's aluminum rather than steel. I don't know whether that's true or not, but it certainly could be. For example, Reynolds 631 and 853 steel both have 0.02% to 0.04% aluminum content by weight, and vanadium and manganese are fairly common elements in steel alloys. I doubt, though, that a very small amount of aluminum would make VALite measurably lighter.
Alloying of Steels
"Aluminum is widely used as a deoxidizer. Aluminum can control austenite grain growth in reheated steels and is therefore added to control grain size. Aluminum is the most effective alloy in controlling grain growth prior to quenching. Titanium, zirconium, and vanadium are also valuable grain growth inhibitors, but there [sic] carbides are difficult to dissolve into solution in austenite."