I imagine they will go ahead and future proof it by doing the digital masters in 4k resolution.
To do visual effects for a Blu-ray release and future syndication in HD would happen in 1080p not 4K. Only tentpole feature films get a 4K pipeline due to the additional rendering needed and storage. Most feature films are still mastered at 2K. Sure I'd love to see Trek at 4K but 1980s TV series Trek is just not going to happen. Be realistic.