Personally I hope they keep the 'no-move-at-0-stamina-when-encumbered' mechanic. It all comes down to planning and managing weight and stamina. There are tools to address such things (like the cart) so it is not like players have no options.

If you choose to toss and move that option exists as well, but the no-movement thing is a good risk vs reward mechanic. Do you risk getting caught by mobs with 0 stamina and unable to move? And if you toss something to become 'unencumbered' and able to move again will your stamina replenish fast enough to save your hiney?

And I believe the raven tells the player about encumbrance and its effects, but I will have to play more attention to the narrative to see if it mentions no movement.