The announcement of this rule change with examples are at the bottom of the article. To summarize:
In the current rules, if you attack with a creature and it gets multi-blocked, once your opponent locks in their blocks, you choose the order of blockers immediately. During the combat damage step, you must assign enough (big asterisk on “enough”) damage on the first creature before you can assign damage on the next.
Starting with Foundations, you don’t choose an order for the blockers. During the combat damage step, you will just distribute damage however you want.
This weakens multi-blocking as a defensive option.
We will one day speak of blocker order like we do damage on the stack.
Wow I never would have expected this change, or that this was even something WotC was discussing. This feels like a massive change and really hurts defending players.
Their justification is essentially:
Not sure how it’s any more or less intuitive or how it adds any more rules baggage than the new rule creates, they just hand wave these things and gloss over the reasoning. Curious how it develops but off the cuff not really happy about this change.