If the redirects were server side (setting the Location header), a blank referrer remains blank. Client side redirects will set the referral value.
From Twitter’s POV, there’s value in more fully conveying how much traffic they send to sites, even if it minorly inconveniences users.
A location header is nearly unnoticeable, a meta refresh page gives you a flash of a blank interstitial screen.
(Not that I had the same annoyance, just explaining the difference to the end user of the two approaches)
If the whole purpose of it is to have browsers send a Referer header, I don't think it's that bad. Even from a privacy perspective, you can configure browsers to not send that header anyway.