That scene is not a cliffhanger, because the scene brought up in that chapter is resolved, though it raises a new issue, because readers don't know whether the chapter survived the attack or not (they're essentially two separate issues, not a continuation of the one threat).
That is the very definition of a cliffhanger.
Basically, a cliffhanger is the technique of ending an installment with the reader kept in suspense - in an immediate sense, not just over the final resolution of the overarching plot of the story - often about something that was only just presented to them.
Michael Louecks has a habit of doing this in his AWLL series, with small ones often at the end of chapters, and large ones at the end of books. At the end of a chapter, someone will say or do something surprising, and we have to wait until the next day to see how it shakes out. The end-of-book ones are generally the main conflict for the next book being introduced, and we're often left wondering not just how it'll be resolved but what exactly happened and to whom. Want to find out? Read the next book!
(I'm actually not a fan of those, because the gap between books is too long. By the time the next book is actually available to read, the suspense has worn off and I've pretty much forgotten about the cliffhanger. When the next book starts posting, it's not, "Oo, I get to see what happened!", it's, "What was happening again? Oh, right. That.")
Cliffhangers have been used in serials forever, as a technique to keep the audience coming back. (Or, in 1001 Nights, to keep the audience from killing the storyteller.) They're not intrinsically bad, though they can get annoying when handled ham-handedly.
My favorite example of how not to cliffhanger is from a Dan Brown novel. A main character boards a helicopter that's going to take her to meet with the President, and then the chapter ends with an ominous, "... but the helicopter would never arrive at the White House." (Quoted from memory, may not be exact.)
And then the PoV switches to the other main character for a while. When we finally get back to the first character, we discover that the reason that the helicopter doesn't arrive at the White House is that it wasn't going to the White House. The character was meeting the President somewhere else. This was the plan all along, nothing untoward occurred with the helicopter flight, and that line was included solely to set up a completely artificial cliffhanger.