Tab complete with KSH in Emacs mode without bindings
bind is Bash/readline-specific.
From the ksh faq,
Q6. Does ksh support file name completion?A6. Yes, it does. The default key binding is <ESC><ESC> however, starting with the 'g' point release, <TAB> also works for completion. Note, the vi users need to set -o viraw in order to get <TAB> completion to work.
ksh93g was released in 1994-04-30, so I'm quite surprised if it doesn't work for you... what's your ksh version?
As you found out, key binding was introduced in ksh93,
Q5. What are the major new features of KornShell 1993?
A5. The only major new interactive feature is key binding. ... (KSH-93 FAQ)
In emacs mode, hitting
<ESC>= gives you a list that matches the text you have typed up to that point.