The Samsung Galaxy Watch4 and Watch Active4 are expected to be announced in the second quarter of this year (April-June). They may mark an important shift in strategy for Samsung as the company is expected to replace Tizen with Android.
It appears that the 3C has certified a 240 mAh battery for use in the SM-R880, which is presumably the 41mm version of the Galaxy Watch4. For comparison, the 41mm Watch3 has a 247 mAh battery, the 45mm one steps up to 350 mAh.
This certification also suggests that the new smartwatches will be unveiled sooner rather than later at some point in the next three months.