Nothing definitive, but I think a few years ago having multiple domains on same IP was a big red flag... but now, with the shortage of IP addresses, web hosts are instructed to use name-based hosting wherever possible, and individual IPs are (in theory) only supposed to be used when there's a justifiable reason (i.e., SSL cert)

So it would seem that penalizing someone for following ARIN's directive on IP address conservation would be stupid. Doesn't mean it isn't happening, though.