Yes whatsapp still on even you removed old sim card and put in new sim card.
Whatsapp cannot be use to log in or log out anytime. Its not like wechat where you can log in and log out with multiple account by just using that 1 wechat app.
Whatsapp function like 1 app for 1 whatsapp account only.
Whatsapp only can activate or deactivate account.
If you want to register new whatsapp account for your new number, you have to deactivated your 1st whatsapp account on old number 1st, then only can register new account for your new sim card.
Your old whatsapp chat history will gone if you dont do chat backup. Can find backup option on setting. If got backup then no need worry about chat gone or not. So please do chwt backup 1st before proceed to deactivated.
Edit: Worried old whatsapp chat histort gone? Unless you register back whatsapp account for old number on same fon then ok, because chat history all saved on that fon, inside google cloud under your email address that you used to registered that fon.
BTW, check your semakpon if can duplicate 2nd whatsapp app. Most semakpon now a day have and support dual apps, where you can have 2 whatsapp account on 1 fon.
And BTW, you still can register new whatsapp account even without the sim card in the same fon, as long as you got 2nd fon to turn on your 2nd sim card, whatsapp will send activation code to your new sim card on other fon, no problem. Then you just enter that activation code received on 2nd fon into whatsapp app on the 1st fon.
So wanna have 2 whatsapp account on same fon? Check your semakfon got support dual whatsapp app or not.
Thanks for taking the time to reply. I need to digest this !