Absolutely smart to have your resume ready. When my dad’s company merged in the 2010s, they announced very publicly and loudly that nobody’s job was at risk. About 25% of his pre-merger colleagues were let go within six months.

Not to say that’ll happen where you are, but take any promises about security with a huge grain of salt. If you ever start to feel “weird,” and that management is treating you differently, be proactive.