flight number is not a major change if nothing else changes or if the previous flight number isnt reassigned to another route. If your flight to Hawaii (OGG) changes numbers from 802 to 862 but things pretty much stay the same....no big deal unless all the sudden at the same time as 802 was changed to 862...802 has become a flight number to LIH then there would probably have to be a reissue because the system is going to think your on 802 to LIH. The reason I know that a flight number change doesnt reissue is because its happened this year to me on my many of changes so far between December and now for a trip in October to OGG. After four changes and one being merely a flight number change I still show up as a Gold on the PNR. I didnt not requalify for gold for 2013 but after 4 changes its still in the PNR. The good news is I should make gold again in 2014