Apple Watch headphones can use the charging tip of the iPad.
In Apple's product line, whether it is iPhone, iPad or Apple Watch, the charging protocol used is the same, that is, PD fast charging protocol. Therefore, using the charging head of the iPad to charge the Apple Watch headset is theoretically possible.
However, due to the low charging requirements of the Apple Watch headset, charging it using the iPad's charging head may cause the charging speed to be too fast, which can affect the battery life of the headset. Therefore, in order to protect the battery life of Apple Watch headphones, it is recommended to use a dedicated charger when charging them.
The earphone should work, but the watch probably won't. The watch is wireless