Can I use regex in allowedFileTypes

Uppy
1 
    const uppy = new Uppy({
  debug: true,
  autoProceed: false,
  restrictions: {
    allowedFileTypes: ['image/[^svg]']
  }
})
2

You can’t, only file extensions and mime types. You could use the onBeforeFileAdded option to add your own checks. For example:

const uppy = Uppy({
  onBeforeFileAdded (file) {
    if (!file.type.startsWith('image/')) {
      uppy.info({ message: 'You can only upload images.' }, 'error', 3000)
      return false
    }
    if (file.type === 'image/svg') {
      uppy.info({ message: 'You cannot upload SVG files.' }, 'error', 3000)
      return false
    }
    return true
  }
})