Traveling to Korea with special entry procedure because of COVID-19

According to the Korean government, a special entry procedure has been set for travellers from 5 European countries including The Netherlands. As an extension to some Asian countries.

More info provided here by the Korean Embassy in The Netherlands on Facebook

All travelers, both Korean and foreign nationals, from above countries are required to fill out Health Questionnaire and a Special Travel Record Declaration, which will be distributed onboard, including their contact information and address in Korea.

At designated separate entry halls, immigration officials will collect the Health Questionnaire and will check travelers’ temperature, whether the travelers can be reached via the mobile phone number provided, and whether the travelers have downloaded ‘Self Diagnosis Mobile App’.

As far as I am aware, you can only rent or obtain a short duration Korean SIM after passing immigration and security. Therefor I will not have a Korean phone number when they check if my phone is reachable in the designated entry hall. Before swapping SIM cards (foreign SIM to Korean SIM).

I will be able to receive text messages and call through roaming, but after I swap my SIM I will have a different phone number. Will this be an issue for my upcoming travel?