Looks like the Welcoming DVD Edition is back in the news with a new release date of 25th March 2015: (Information unconfirmed, via GDREIRA):
Previous information:
[Pre-Info] BIGBANG WELCOMING 2015 3DVD Collection
[Pre-Info] BIGBANG WELCOMING 2015 3DVD Collection.
2015?1?14???
BIGBANG’S 2015 WELCOMING COLLECTION DVD[DVD3??]
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No further details are available at this point.
Info via yuuka4893
FULL details for this release can now be found here: [Release] ?BIGBANG’S 2015 WELCOMING COLLECTION DVD? Japan edn release 2015-03-25