After the panic buy I've never seen a toilet paper shortage anymore. I therefore doubt your theory of correlation. Maybe it was so in the us but it definitely does not correlate for everyone.
With the world shutting down the companies that supply those kinds of places had a warehouse full of inventory and most of their usual customers either were entirely shut or going through a lot less product.
I'll wager your grocery store called one of them up and got a few pallets to resell, creative move on their part.