If there would be a next change in the game, I would like to see a mechanics changed meaning as much fun it is to deck build, it's repetitive. Adding other types of cards like equipments, field, spells, not omly can contribute to the lore but may be better in terms of gameplay.
Spells can be something like an instant but sticking effect like inflicting poison to each opponent at the cost of 2 monster slots or inflicting 1 damage to all opponent at the start of the turn, technically killing 1 health units before gaining effects, etc.
Equipments can be placed on board and affects the monster beofre it essentially "equipping" it providing bonus stats and abilities. If the monster gets destroyed, the equip card gets destroyed.
Tldr, a change in the core mechanics may bring new excitement to the game rather tahn just new abilities. There's a reason why yugioh is already almost 30 years and has changed their "rules" i think 5 times now. They introduce not omly new effects but new mechanics like synchro fusion pendulum and recently linked monsters.
Tldr2 i think change in mechanics in splinterlands allow the gane to not be too repetitive and make it more challenging and exciting. Also, card updates like changing card's stats may also be good to make other not so playable cards like supply runner get the spotlight once in a while.