Account import template missing phone type

Summary:

Account Import object does not have the attribute PhoneType.

Content (required):

Hello,

We have a requirement to remove phone numbers from some accounts. The import management tool allows nullifying individual attributes- PhoneCountryCode,PhoneAreaCode,PhoneNumber,PhoneExtension - by using the #NULL value in the csv file. 

However there is no way to remove the PhoneType field as this is not mapped in the import object - Account.

I wanted to know if there is a way to update this field, or can it be left untouched (with the value on) on the account records? Would it cause any issues if left as it is.