What was asked is, what if the customer initiates NoTouch, is he committed to using Flashmagic to restore the system ?
Not really, NoTouch activates the ISP ROM in the P89C51Rx2/66x and if you use WinIsp, FlashMagic or HelloDolly to feed the ISP ROM code is irrelevant as long as the format fits the download ROM. If, for some reason you want to use a Flash stored "private" download, NoTouch does set the boot vector, you are welcome to modify that one line.
I thought the answer was yes, but then reading your reply you said "read the other article"... but now you say that it would not be implemented in a shipped system, that there is only one method.
The method referred to in doc2 is an "emergency exit". NoTouch is activated e.g. by a command string from the UART which requires that your program is functioning, doc2 enters at the absolute beginning of your code, so if you have non-functioning code that does not get to where NoTouch activates (e.g. you screwed up the UART receive) Doc2 will still activate ISP BUT Doc2 requires a pin pulled low, something you do not want to request from a customer.

Hope this clears it up

Erik