With the main Batman writers usually staying on the book for 4-5 years (at least Morrison, Snyder and King stayed that long) that would be really not a good idea.
Not every character needs to appear in every event, but no character should "put on the bus" for more than a year (at max maybe two years).
And in the past the writers haven even with a reduced cast often not really managed to use them all properly (for example in the Eternals).