Searched, but there were no reports detailing this behaviour. Do not suggest otherwise.
Unlike with grass blocks, it seems as though podzol stays podzol even when a tree is immediately on top when generated with the world.
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For player-grown trees, this was intentionally fixed so that the podzol stays: MC-57884
Also, podzol in general behaves differently than grass does not decaying when something is on top of it.
Can confirm in 20w51a.
Can confirm in 21w03a.
Can confirm in 21w05b.
Can confirm in 21w06a.
Can confirm in 21w07a.

Can confirm for 1.16.5. Also occurs when you grow a 2x2 tree and it generates podzol below it.
Can confirm in 21w13a.

Can confirm in 1.18 Pre-release 7.
Can confirm in 1.18.
Can confirm in 1.18.2.
Can confirm in 1.19.2.