It's not likely but it's a possibility. Mirrorcle World had an INSANE weekend boost after almost losing out to Shuchishin but that was thanks to concerts, it seems.
Here's a look at Mirrorcle's first week:
Spoiler:
[1st Week]
2008.04.07
Position: #1
Index: 21,355
Estimate Sales (1st Day): 21,355 x 1.75 = 37,371
2008.04.08
Position: #1
Index: 16,180
Estimate Sales (2nd Day): 16,180 x 1.75 = 28,315
2008.04.09
Position: #2
Index: 9,332
Estimate Sales (3rd Day): 9,332 x 1.75 = 16,331
2008.04.10
Position: #2
Index: 4,997
Estimate Sales (4th Day): 4,997 x 1.75 = 8,745
2008.04.11
Position: #2
Index: 4,324
Estimate Sales (5th Day): 4,324 x 1.75 = 7,567
2008.04.12
Position: #2
Index: 12,772
Estimate Sales (6th Day): 12,772 x 1.75 = 22,351
2008.04.13
Position: #1
Index: 16,638
Estimate Sales (7th Day): 16,638 x 1.75 = 29,116
I think Ayu could probably still snatch the number one in the coming days. It's still way too early to call IMO.
Another odd example is when HEAVEN was #2, #3, and #4 in the first week before ending up as #1 for the rest of the week resulting in a #1 at the end of the week.