I checked the Bell Labs history ("Switching, 1925-1975") to see what was said preliminary false switchhook pulsing. There wasn't much, and I couldn't find anything in the 1875-1925 book.
For SxS offices:
"arrangements were developed to prevent wrong numbers due to preliminary pulses which might be falsely generated at the start of a call when the receiver is first taken off hook. This also resulted in the standardization of 11X service codes compared with X11 for the panel system.
Ref: "Counteracting Dialing Errors in the Step by Step System", Bell Labs Record, January 1929, p 198.
Implementing DDD:
To add long distance to an SxS office on the basis of area code (0/1) would've been expensive due to adding senders/registers or building out the switch train. The easier way was to add 1 as a prefix. "An exception was the elimination of preliminary pulse detection, a feature that was abandoned with the obsolescence of the desk stand telephone."
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I am not sure why panel switching didn't have the problem that SxS since both systems in their early days used desk-stand (candlestick) phones.
Unfortunately, I don't have easy access to library issues of Bell Labs Record to study this further. I hope someday they put the record on line; it would answer many historical questions.