On 27 Jan 2016, at 9:49, Greg Aaron wrote:

A) The current registrar and the current registrant are not the only parties
with an interest in a domain's expiration date. For example, other people
may want that domain when it expires. Gaining registrars like to see the
expiration date when processing inbound transfers.
B) A domain's expiration date can be gotten via EPP <info> command. No
reason to show expiration date in a <info> command but not in WHOIS.

Wouldn’t (B) negate the “Gaining registrars” part of (A) as an argument?

Also, given the prevalence of auto-renewals, I would argue that WHOIS as it is today don’t work for prospective registrants interested in an unavailable name. They really have no further clue about when the domain will be available by looking at the expiration date alone. To that effect, showing the pendingDelete status in the WHOIS record is better for them, as it’s clear that the name won’t be auto-renewed and will become available at some point in the (near) future.