I think it might be: Alt(ernate) + A(li) + Ba(ba)

I figured it is pronounced "alt tabba"; it's so handy that you keep it an alt-tab away.

Perhaps Ogden Nash wrote a poem about it?

In an alternate universe, Altaba Inc propably translates to Detroit Online. Once the center of The Web, now a shrinking core surrounded by blight.

It's Canadian for changing tasks: alt-tab, aye?

That word is spelled "Eh", eh.

Alt-Tab-Away?

Makes me thing "Alternate Ali Baba".

Amusing since "Baba" is well known as either a sponge cake, a grandma, a holy man, father, baby or blanket [1].

so what's an alt-baba?

[1] https://en.wiktionary.org/wiki/baba#Noun