It seems like it's fully given up on maintaining a native desktop client for Mac. That being said, there's no hint suggesting Twitter will release a more improved replacement in the future. There really isn't any recourse for now, and Twitter is even endorsing that Mac users access the web version for now. 'So, starting today the Twitter for Mac app will no longer be available for download, and in 30 days will no longer be supported.'
'We're focusing our efforts on a great Twitter experience that's consistent across platforms,' the Twitter Support account said. Twitter Pushes Mac Users To Use Web Version
