That '2000 peer ASN's' value is likely very, very inflated. I have prefixes that would look like I am peering with 3549 directly in many places that I do not. 

L3 has for some time had a partial as-merge community that you can set so that if you announce a prefix to 3356, they'll mirror it over to 3549 in the same location and strip 3356 from the as-path. The reverse also works for an announcement to 3549 mirrored over to 3356. They're doing some inter-as option c juju to make all that work. 

Doesn't change the point that 3549 is still around 8 years later and likely will be for 8 more, but yeah. :) I'm sure efforts to make that happen have a plethora of roadblocks such that it would cost 10x more to get rid of it than it would to just leave it as is and just shrink it when possible. 

On Fri, Jun 7, 2019 at 12:11 PM Mike Hammett <nanog@ics-il.net> wrote:
I wouldn't expect them to be integrated for at least another decade. Global Crossing AS3549 still exists with over 2,000 peer ASNs, yet Level 3 acquired them in 2011. Time Warner Telecom was acquired in 2014 and it still has 89 peer ASNs.

Centurylink bought Digital Teleport in 2003 and their ASN is still out there.

From: "Darin Steffl" <darin.steffl@mnwifi.com>
To: "North American Network Operators' Group" <nanog@nanog.org>
Sent: Friday, June 7, 2019 11:01:46 AM
Subject: CenturyLink/Level 3 combined AS

Hey all,

Are there plans for CL and Level3 to combine AS's into one network? 

If not, do they actively peer and route traffic through each other's networks at least?

Basically we're looking at picking up 1G of CL and wondering if it's near the same quality as Level3 in terms of latency and packet loss.

Thanks

--
Darin Steffl
Minnesota WiFi
507-634-WiFi