Nah, he's still not done with his career yet. Anyway, my generation will still be around on the internets in full force to smack some sense into the noobs who'll claim that close to 100 international centuries is a stroll in the park. Reckon Warne would have a quiet chuckle if he found that a forum had him ranked higher than Sachin. Actually I wouldn't be surprised to see Murali gain at the expense of Warne in that timeframe. If there's anything that'll cause a slide in Sachin's assessment 20 years down the road, it'll be people who haven't been around now taking his average at face value. And that works against Warne (cf Murali) more than it works against Sachin.
I would a little, tbh. I suspect, rightly or wrongly, people will still be discussing the invisible asterisk beside his records for years & decades to come in much the same way as Bodyline still stirs emotions amongst cricket fans (especially those of an English or Australian persuasion) whose parents and even grandparents weren't born when the series took place.
Think Sachin maybe very slightly overplaced at #6. As magnificent a player as he was, he didn't dominate his own era in quite the same way as (say) Grace, Ranji, Hobbs or Bradman did theirs. Had him at #18 ftr and of the chaps I had ahead of him (in no particular order: Grace, Hammond, Imran, Marshall, Warne, Miller, Hadlee, Lara, Weekes, Barnes, Hobbs, Bradman, Gilchrist, Ambrose, McGrath, Kallis & Sobers) only really Lara gave me pause for thought in placing them above him. Just my HO tho, obv.