(According to TFW2005) The 2020 Hallmark Transformers Christmas ornament is G1 Jazz.

Previous year's ornament G1 releases.
2019 - Bumblebee
2018 - Starscream
2017 - Soundwave
2016 - Grimlock
2015 - Megatron
2014 - Optimus Prime

Placeholder for Hooked on Ornaments store (in no way, shape or form am I endorsing this store).