Amanda is right. The meeting organizer will receive only one meeting message. However, if the meeting organizer uses the tracking function to determine who is attending (which is ultimately easier than checking emails), then the response will update.

That being the case, it would be as clear if not clearer to the organiser, and fewer steps, to simply reply "tentative" and then include a message to the organiser stating you will not attend but want the appointment to remain in the calendar for any updates!

An alternative to register an actual decline but still have a record of the appointment is to

1. Open the calendar view for the meeting day (click the "calendar" button on the invite email).

2. Copy the appointment itself and paste the copy (Ctrl+C then Ctrl+V).
Make sure it is the appointment that is selected, not the title. "Successfully" doing this will create a second, conflicting, appointment called "Copy: [whatever the original title was]", which you can open to adjust your preferences for how the time will show, reminders, etc.

3. "Decline" the original appointment, including a message to the organiser if desired. This is the opportunity to ask the organiser to keep you informed of changes or send notes, etc. If the organiser uses the email attendees option, then declined attendees will be updated, however if the organizer updates the appointment per se then updates may be missed if the appointment has been declined.

& Vote up a feature to display or continue to be included in updates to declined meetings to be included as part of Outlook: https://outlook.uservoice.com/forums/322590-outlook-2016-for-windows

Ultimately the best workaround depends on why it was desirable to keep the appointment in the calendar. The copied appointment solution here works if the priority is to remember the meeting was scheduled for a given time to prompt follow-up or in case of a scheduling change that would enable your attendance (the "copy" retains the details of the organiser), without creating confusion for the organiser. The decline and then accept solution in the post above works if the priority is to have updates... but perhaps you should consider the simpler option of just replying "tentative" with a message why and still the advantage of the updates. Any which way you can adjust how the time shows in your own calendar (busy, free, etc.), and reminders, independently of your attendance status.