Hive2 vs Hive3 regexp_replace differences

For a hive2 cluster, I do not have to escape a double quote inside a  regexp_replace  where the  single quotes to start and end the regex.
But on hive3 in order for the code to work, the double quote needs to be escaped (Example to follow).
Why the difference?

-- Works in Hive 2 but not hive3
select  
   id
   , case when
        url rlike '(?i)^https://www.linkedin.com/("?in|pub|company|profile)' then url
            else regexp_replace(url,'^https://www.linkedin.com/','https://www.linkedin.com/in/')
     end as social_url
from db.table
limit 10

-- Works in hive3
select  
   id
   , case when
        url rlike '(?i)^https://www.linkedin.com/(\"?in|pub|company|profile)' then url
            else regexp_replace(url,'^https://www.linkedin.com/','https://www.linkedin.com/in/')
     end as social_url
from db.table
limit 10