Then I'll be the first to congratulate him (obviously for that to happen he has to at least end the year as nº1, a temporary position wouldn't merit it). But it would be a huge achievement. But I doubt it very much.
Just thought I'd add here that the year end no.1 ranking can be just as 'temporary' as a no.1 ranking attained at any other point in the year.
Being number 1 means you're the best player in the last year of play
, whether that's a calendar or non-calendar year. There's no guarantee you'll continue to be the no.1 beyond this point, irrespective of whether you attain the ranking at the end of the year, or in the middle of the year.