I think you're being a little unrealistic here tbh... whilst it seems that respawn did care about this game and, given the resouces they were given, they did an amazing job. However I think it's fair to say that EA never really cared about this game... EA threw Respawn on this project because they deicded to axe Titanfall and probably didn't know what else to do with the studio. They probably put Respawn onto Apex simply to try and cash in on the Battle Royale and 'cos they had no idea wtf else to do with them... I mean cm'on EA, releasing a FTP game?! Not exactly in character for them? Now most of Respawn have been put onto the new Star Wars game and there is probably simply NOT enough manpower working on Apex to provide such a large community with support as well as changes and updates.
EA clearly never expected Apex to have the sucess it did and didn't put aside the resources necessary to support the game correctly after launch. You're right that making gameplay changes does take a lot of time and testing, and whilst also trying to fix bugs, combat cheaters and manage the community and I think it is clear that respawn are working with very little here. So I think the OP is half right, I think EA don't care about the game, and as interest wanes due to the lack of new content, interesting items and cheating they will simply use that as an excuse/justification to further cut support for Apex.
With EA you can usually count on them to make the worst possible decision in any circumstances and I worry about the future for Apex under their control... it would not suprise me in the slightest if in 3 or 6 months from now we wake up to discover all the servers have been turned off and the game is dead. With a FTP game you can bet they feel no obligation to support the game once the money slows down, and without the resources to provide a more interesting and diverse skins and loot people will not be so inclined to spend money on coins.