Yes, the new Loot Rewards system will be completely tied to the Loot Coins currency.
When designing this new system, we took special care so members who've joined us after this transition can afford to redeem the next Mid and End of Season Rewards while being on the starter ranks.
Long time members will have plenty of Coins to be able to redeem all the new seasonal rewards plus a lot of extra content.
Also, if one of these seasonal rewards is not your cupholder of tea, you may as well skip it and spend your Coins with anything else you prefer 😉.