As long as they have relatively fresh stock and their turnover is decent.
Malts and other grains can remain fresh for a few years, stored in their original sacks.
I'm not so sure about malts stored inside bins, which tend to have relatively large (empty) headspaces while too often lids are left off. So there is exposure to air (oxygen), and if not stored in an air conditioned room, the worst factor in staling reactions,
humidity!
You can always chew a few malt/grain kernels to learn their flavor profile and verify freshness. Just be careful chewing Crystal and Caramel malts and even some Specialty malts, they're usually very, very hard. You don't want to break your teeth. You could crush those hard kernels using (clean) pliers. Wind a piece of (masking) tape over the crushing area of the jaws to ensure they're food safe.
You'd only need about 2 (or 4) oz of each of those malts you're interested in. Aside from chewing the kernels, you could steep those 2-4 ounces of each crushed malt (150-170F) and smell and taste the resulting worts and make ample notes on your perception. It's also useful to team up with one or more other people to exchange those flavor/aroma experiences.
Yet, it remains pretty abstract to translate those single flavors and aromas to what they'd contribute to beer
after fermentation, when there are so many other things going on at the same time, one of them being
alcohol that really changes the perception. Still, a good exercise, though.
Back in my earlier brewing days, while studying for the beer judging (BJCP) course, I brewed a series of small batches of beer (~1.5 pint each) using either a different, single malt, or 2-row plus a specialty/crystal malt for each batch. Save those (larger) mayonnaise and peanut butter jars and/or (soda) bottles!