ALTER TABLE - how to not break data model

hello,

i have created a report that required multiple calculated columns, measures etc. 

the data source is a SQL table (i execute a stored procedure in Power BI to access and refresh the data)

now business requirements require two additional fields to be added to this table in the source. 

will my data model break if the same stored procedure is updated to include this ALTER TABLE? will all my calculations show errors?

i want to keep all calculated columns the same, all measures the same (none of those fields are changing) and just have the source include the two additional fields that i need to perform additional calculations with?

looking for some insight here please and how to achieve this?

thanks,

amrita