If you have been playing for so long and now after this long pause of 27 days, I think, maybe you could wait a bit longer to allow Splinterlands to complete that whole recent change by implementing new Leagues too.

If I could walk in your shoes, I would certainly consider that option before starting selling my cards. Think about it! You may always sell your cards, if the finalization of this whole change by implementing new leagues wouldn't meet and satisfy your criteria. Don't just go without testing the whole package! It's not easy to build such a collection as you have! 😊

Just my 2 cents!