Given that emoji originates from Japanese, it is expected that CJK Unified Ideographs that are in Noto Emoji should use the Japanese character form. However, due to unknown reasons, the ideographs that are in Noto Emoji uses the Taiwan MOE education form. This is unacceptable for Japanese usage. Do note that Taiwan MOE is not the de facto form for Traditional Chinese and similar glyphs to Japanese (called 傳承字形) are used in Taiwan too.

Below is a screenshot from https://rsheeter.github.io/android_fonts/emoji.html?q=note:Japanese . Out of the 15 emojis containing CJK Unified Ideographs, 7 contains the wrong character form and 1 contains design variation in Noto Sans TW/JP. On the left of emoji shows the correct Japanese forms in Noto Sans CJK JP.

The variation in U+1F234 🈴 is acceptable, but seeing that other characters are all using the wrong form, it might be better to switch it over to the JP form too.

Noto Emoji may consider keeping the current emoji and use them in locl, but for Japanese usage the current form is definitely incorrect.