in theory - yes. because Xbox One is capable of supporting mkv.
Xbox One S supported file formatsVideo formats: 3GP video, 3GP2, AVI DivX, DV AVI, AVI uncompressed, asf, AVI Xvid, H.264 AVCHD, M-JPEG, .mkv, .mov, MPEG-PS, MPEG-2, MPEG-2 HD, MPEG-2 TS, H.264/MPEG-4 AVC, MPEG-4 SP, WMV, WMV HD
Audio formats: 3GP audio, AAC, ADTS, MP3, WAV, WMA, WMA Lossless, WMA Pro, WMA Voice
Xbox One S unsupported file formatsVideo formats: FLV, XAVC, XAVC S, H.265/HEVC, MPEG-1, VP8, VP9, MVC, Real Video, Theora, Prores
Audio formats: Vorbis, Opus, AC-3, DTS, PCM, LPCM, FLAC, ALAC, MLP/Dolby TrueHD, DTS-HD
However, most of 4K movies are recorded in MXF/RAW/XAVC, etc. format which the Xbox One S does not support.
Sources:
http://www.multipelife.com/xbox-one-s-supported-file-formats.htmlhttp://open-media-community.com/2016/08/03/enjoy-4k-video-on-xbox-one-s-for-4ktv/