These funds already raised for an exchange, Rijks close followers Jason, Martin, Robby and Bart use delay tactics because these funds will be used for development. Rijk must of made a deal with the florin premine investors that Gulden will pay for the development.
Below is the funding raised for a exchange listing and always excuses for it not to be used on exchanges.
https://www.blockchain.com/btc/address/bc1qzeutgh895tj9wzpdt6kg50pcmeguk4ddp0tj82Those funds were raised 90% by dev rewards. At the time price was over 2 cents and there was an excess of funds coming in. Gab and Rijk decided to put it into btc. Which in hindsight was a great decision because if it was kept in Gulden then it would be worthless now.
The funds were raised for a specific exchange: Bitvavo. For a NLG Euro pair. Using those funds for a exchange like XT makes no sense.
It does not make sense for Florin either but when users look at coinmarketcap and see more exchange they will have more confidence to invest.