The new Weaving effect has potions to go along with it, and in the latest pre release (1.20.5 pre5), Weaving now has a use for players, as it decreases the effect of cobweb slowdown on the user, however the potions are completely missing extended versions (made using redstone on normal potions). This is unlike all other potions in the game that are obtainable in survival, which is why I believe it is a bug.

This bug also applies to the other new effects' potions, however I believe it is likely to be intended for them as those potions have little direct player use, unlike Weaving.