OK, 2 paragraphs of background: Currently (and for the past decade) people in Gaza have had no control over their land or future - they are entirely at the mercy of the Israelis. You might see references to this as the "right to self determination." Palestinians in Gaza cannot leave, cannot trade with other countries, etc. Israel controls all land crossings and has a naval blocade on the sea, inspects all goods coming into Gaza, including limiting what goods Gazan people are allowed to possess. Attempts to give Gazans goods have been met with extreme hostility - see, for example, the freedom flotilla in 2010: https://en.wikipedia.org/wiki/Gaza_flotilla_raid

If a country controls every aspect of your territory, that is by almost by definition an occupation. This article talks in depth about the definition of an occupation: https://www.atlanticcouncil.org/blogs/menasource/gaza-israel-occupied-international-law/ (note atlantic council is a right-leaning source, https://mediabiasfactcheck.com/atlantic-council/). Here's a second source from the UN, back in 2022 before the current events. https://news.un.org/en/story/2022/10/1129942

So to answer your second question, "liberated" does imply the removal of an occupier. Under almost every definition, Israel is occupying Gaza and the West Bank.

To answer your first question, is it advocating for the dissolution of Israel? In general, no (yes, some people want that, don't "not all x" me). But if the real question is where do we go from here, how do we "stop the murders"?

If Israel relinquished control over the Gaza Strip and the West Bank, that would be what people generally call the Two-State solution. This is NOT the dissolution of the state of Israel at all, and in fact enshrines the state of Israel, but at a scale that give it by definition less than the entirety of Israel+Gaza+West Bank. While this has been the "liberal" position in the US, the US keeps voting against a real Palestinian state (https://apnews.com/article/un-vote-palestinian-membership-us-veto-8d8ad60d8576b5ab9e70d2f8bf7e2881). In other words, what we say we want does not match up with our actions. And Netanyahu has reiterated that this will never happen under his watch. https://apnews.com/article/israel-hamas-war-news-01-18-2024-73d552c6e73e0dc3783a0a11b2b5f67d

So if a 2-state solution is off the table by both the US and Israel, where does that leave us? Without a two-state (or one-state solution, with enshrined rights for Palestinians), the murders of Palenstinians will continue unabated. For example, in the West Bank (the other occupied territory), more than 200 Palestinains were murdered in 2023. https://www.doctorswithoutborders.org/latest/palestinians-west-bank-2023-was-deadliest-year-record https://edition.cnn.com/middleeast/live-news/israel-hamas-war-gaza-news-12-16-23/h_b60eefa90fd1779f9b2b8cbf8d823c41

Apart from this, Israel would basically have to either push all the non-Jewish populations out of Israel (known as ethnic cleansing https://en.wikipedia.org/wiki/Ethnic_cleansing) or kill them all.