What you're apparently referring to is slight change in Hamas charter in 1997.
In fact, what they actually said was "Hamas advocates the liberation of all of Palestine but is ready to support the state on 1967 borders without recognising Israel or ceding any rights"
i.e. they would support the creation a Palestinian state within 1967 borders in the interim but not give up their fight for the rest of Israel.
This "softening" (as one left-wing newspaper called it apparently unironically) was in contrast with their previous stance which would reject a Palestinian state offer if it was based 1967 borders.
They have never gone back on their stated aim to reconquer all of Israel and never indicated they will tolerate Israel existing.
In fact, what they actually said was "Hamas advocates the liberation of all of Palestine but is ready to support the state on 1967 borders without recognising Israel or ceding any rights"
i.e. they would support the creation a Palestinian state within 1967 borders in the interim but not give up their fight for the rest of Israel.
This "softening" (as one left-wing newspaper called it apparently unironically) was in contrast with their previous stance which would reject a Palestinian state offer if it was based 1967 borders.
They have never gone back on their stated aim to reconquer all of Israel and never indicated they will tolerate Israel existing.