What are the drop rates for the 6 items added in today's update? Is the chance to receive each item the same?
No, the drop rates between different items are almost certainly not the same.
In the last two days of idling on two accounts (two weeks' worth) I've got:
This is hardly evidence but an example of what to expect. Some items are likely more rare than others.
Most possibly Meet The Pyro items. Think about it, the burned dairy? The weapons dont have any stats and aren't even equitable. Just Valve trying to hint towards Meet The Pyro. I'm getting on to try to collect said items.