It's not purely a question of recency bias though, is it? There are just different ways to assess it.
On a numerical basis, on something close to how much of an 'upset' it was, a more abstract feeling or a combination of the above.
Saturday is literally our worst statistical loss in the league in the sense that it is our biggest numerical loss in the lowest division we've been in and whilst the club is in arguably one of the most precarious positions of it's existence.
You've mentioned the loss to Wycombe and the fact that that started a collapse into league 1, but then how is a 4-0 pasting at home after that sort of long systemic collapse not worse then the one at the beginning? For what it's worth I remember the Wycombe loss very well. I remember seeing the scoreline on ceefax as a kid and the video footage after on BBC Full Time. I'm not convinced people will remember the Oxford loss so much, but it's a bit contrarian to be suggesting the inclusion of Oxford is not even close.