A new approach to a new scenario is not a shift in Hashkafa. What zionist groups wanted and did in Europe before the war is entirely different from the new reality.
Unless you are Satmar and insist that Shalosh Shvuos are tantamount to Avoda Zara and worse than Chilul Shabbos, the whole issue with the movement was the havoc they caused and his they pulled thousands away from their their tradition.
Now, there is a state of Israel, and a country full of, and run by, Jewish people. This is not an organization. In fact, it is silly to call them Zionists. This is a title remembered mainly by the anti-Israel crew.
A Rebbe who is ממלא מקום is not merely a Rosh Yeshiva’s son who can repeat what his father said. He evaluates the scene, understands the true and inner motives of the previous rebbes, and decides accordingly.
There are strange things going on. Yes, it’s strange to me. However, this is an entire Kehilla. You aren’t getting then to nice away from where they are. It seems more about wrong semantics than anything else, anyhow. The ideas aren’t foreign to Chasidim, but others never publicly insist on such things and surely not with such terminology. But if you get where they are coming from, you can take their words for their original meaning.