It's not a big deal... but it's so weird.
When I clicked on my season rewards in Splinterlands there was a massive wait... it scrolled for ages... so I left and came back... saw my chests and opened them... had a look, got excited and then the site went down immediately for maintenance... so maybe the info never made it to Peakmonsters. I've definitely checked my card collection and the new reward cards are there... so it's all good.