Without knowing, I suspect the reason is a lack of staff. Over a hundred devices are maintained by I don’t know how few developers. And monsieur @rhunault can’t duplicate either.
The Galaxy Tab S2 9.7 Wi-Fi (2016) ‘gts210vewifi’ is maintained and nurtured by the official LineageOS team via LOS 17.0. But an external oneman show is developing and maintaining even based on LOS 16.0 and simultaneously LOS 17.1 - even with 'D’aily OTA updates. So there is plenty of activity.
Whether the announcement of official /e/ OS ‘Q’ support from 9th week 2021 will become a reality, I guess we will have to wait with patience and besonnerheit.
Until then, I will switch from LineageOS back to argon3030’s unofficial /e/ OS ‘9-Pie’ ‘Q¹’, because degoogled /e/ OS ‘9-Pie’’ is my personal favourite. Thanks for building and sharing, @argon3030
¹Update
‘9-Pie’ instead of ‘Q’ [kuː],
Thank you for the correction, @argon3030. It doesn’t have to be AOSP Android 10. A well-maintained AOSP Android 9 pie is also a fantastic degoogled /e/ OS ‘P’ edition.