I think animals could still matter a lot (or the interpersonal comparisons are undefined) on non-hedonic welfarist views:
On objective list theories, see Theories of Welfare and Welfare Range Estimates by Bob Fischer.
On preference- and desire-based theories, see my posts Which animals realize which types of subjective welfare? and Solution to the two envelopes problem for moral weights. Some more background is in Types of subjective welfare.
I think animals could still matter a lot (or the interpersonal comparisons are undefined) on non-hedonic welfarist views:
On objective list theories, see Theories of Welfare and Welfare Range Estimates by Bob Fischer.
On preference- and desire-based theories, see my posts Which animals realize which types of subjective welfare? and Solution to the two envelopes problem for moral weights. Some more background is in Types of subjective welfare.