As noted by iMore, Apple has adjusted the trade-in values of many of its products on the Apple Trade In webpage. For example, iPads are now actually worth more than they were previously, but other devices like Mac have dropped in value.
The iPad Pro is now worth up to US$525, up from $500. The iPad Air has gone from $210 to $250, the iPad from $200 to $240, and the iPad mini from $175 to $205. Apple has also boosted the price of its Apple Watch models ever so slightly. The Series 4 is now worth up to $150 (up from $140), the Series 3 is now worth $95 (up from $85), and the Series 1 is worth up to $35 (up from $30).
Alas, the MacBook Pro is down from $1,760 to $1,530, the MacBook Air is down to $630 from $730, the MacBook is down to $380 from $450, the iMac Pro is down to $3,040 from $3580, the iMac down to $1,180 from $1,390, and the Mac mini is down to $830 from $930. On the other hand, the Mac Pro has received a big bump up to $2,930 from $1,490.