That’s a distinct possibility. The pro-independence side also have the regional electoral system in their favour, which allowed them to gain a parliamentary majority last time despite winning only 47.8% of the popular vote. To those that don’t know, the region has something akin to the US electoral college system which gives rural areas (where support for independence is strongest) a disproportionate number of seats.
The best hope for a swing to the anti-independence side is that enough of those that were somewhat persuadable and voted for pro-independence parties last time knowing there’d be a final day of reckoning ahead will balk at doing so again, now that the prospect of independence and the uncertainty it will entail is so much more real.
I suspect there won’t be any clear winner with both sides claiming the other has no mandate.