RuthNY, I'm with you here - I'm not inclined to type a script unless there is clear evidence of the need for a modifiable copy.
Given I've spent most of the last several years doing new or extensively revised works, the Word or Final Draft file IS important in rehearsal (and afterward)... but as MatthewShiner pointed out, an original file usually comes to Stage Management already typed up in these situations, and once rehearsal begins the file is maintained by a PA or ASM or other script secretary. I've never received the script for a new show ONLY in hard copy (thank goodness!)
kmc307, I can honestly say the length of the run is irrelevant to me. I've done new shows with a run well under forty performances, and without a master electronic file, we'd have lost tons of invaluable rehearsal time.