The MS355s (and others covered by the end of sale notice) will be supported for over 5 years. I totally agree it is a tricky time right now. We had the same choice and got the 355s as the 9300s weren't fully featured yet. I'm sure it will be soon that these features arrive, the native IOS-XE wasn't until 2025 in February, but arrived in October so there's hope!
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