We do not really have any cause to celebrate another breakaway from the Likud by Gideon Sa'ar. If it was a breakaway that moved towards the left of centre-right with a new approach then we could celebrate.
Gideon Sa'ar is even more right-wing than Netanyahu. At the end of the day, we notice a plethora of right-wing to extreme right-wing parties. These parties are Yamina, Likud, Sa'ar's yet-unnamed new party, Yisrael Beiteinu Party, Jewish Home Party and of course the ultra-Orthodox Parties, Basically all these parties have similar ideologies and do not weaken the right-wing bloc. They may even form a coalition after the upcoming general elections, despite denials of serving under criminal suspect, Netanyahu, who stands a strong chance of being re-elected.
The credibility of politicians in Israel is erratic and after elections, the ball game changes as well as their promises to their voters as we witnessed in the aftermath of the last elections.
These upcoming elections will bring no significant changes. It is a right-wing oriented election. The left-wing in Israel will be weakened even further. Basically the Israeli electorate is moving further to the right and the position of the centrist right-wing parties may even make a shift to a right-wing coalition. Even the Joint List, apart from the Hadash faction is certainly not left but Arab nationalist rather than egalitarian for all Israel's citizens. This leaves us with the left-wing Meretz Party that may get 6 seats according to the latest polls. The Labour Party will not have any representation in the Knesset.